diff --git a/app.py b/app.py
index fa92e882..937cab28 100644
--- a/app.py
+++ b/app.py
@@ -491,12 +491,12 @@ from modules.auth import (
 )
 
 # i18n language detection middleware (sets per-request language from Accept-Language header)
-from modules.shared.i18nRegistry import _setLanguage
+from modules.shared.i18nRegistry import _setLanguage, normalizePrimaryLanguageTag
 
 @app.middleware("http")
 async def _i18nMiddleware(request: Request, call_next):
     acceptLang = request.headers.get("Accept-Language", "")
-    lang = acceptLang[:2].lower() if len(acceptLang) >= 2 and acceptLang[:2].isalpha() else "de"
+    lang = normalizePrimaryLanguageTag(acceptLang, "de")
     _setLanguage(lang)
     return await call_next(request)
 
diff --git a/modules/datamodels/datamodelUam.py b/modules/datamodels/datamodelUam.py
index 9597eb2f..7bac8672 100644
--- a/modules/datamodels/datamodelUam.py
+++ b/modules/datamodels/datamodelUam.py
@@ -14,7 +14,7 @@ from typing import Optional, List, Dict, Any
 from enum import Enum
 from pydantic import BaseModel, Field, EmailStr, field_validator, computed_field
 from modules.datamodels.datamodelBase import PowerOnModel
-from modules.shared.i18nRegistry import i18nModel
+from modules.shared.i18nRegistry import i18nModel, normalizePrimaryLanguageTag
 from modules.shared.timeUtils import getUtcTimestamp
 
 
@@ -243,17 +243,12 @@ class User(PowerOnModel):
     )
     language: str = Field(
         default="de",
-        description="Preferred language of the user (ISO 639-1 code: de, en, fr, it)",
+        description="Preferred UI language code (must exist as UiLanguageSet; loaded from /api/i18n/user-language-options).",
         json_schema_extra={
             "frontend_type": "select",
             "frontend_readonly": False,
             "frontend_required": True,
-            "frontend_options": [
-                {"value": "de", "label": "Deutsch"},
-                {"value": "en", "label": "Englisch"},
-                {"value": "fr", "label": "Französisch"},
-                {"value": "it", "label": "Italienisch"},
-            ],
+            "frontend_options": "/api/i18n/user-language-options",
             "label": "Sprache",
         },
     )
@@ -261,10 +256,9 @@ class User(PowerOnModel):
     @field_validator('language', mode='before')
     @classmethod
     def _normalizeLanguage(cls, v):
-        """Normalize language to valid ISO 639-1 code."""
+        """Normalize to primary language subtag (2–8 letters); default remains ``de``."""
         if v is None:
             return "de"
-        # Map common variations to standard codes
         langMap = {
             'english': 'en', 'englisch': 'en',
             'german': 'de', 'deutsch': 'de',
@@ -274,11 +268,7 @@ class User(PowerOnModel):
         normalized = str(v).lower().strip()
         if normalized in langMap:
             return langMap[normalized]
-        # If already a valid code, return as-is
-        if normalized in ['de', 'en', 'fr', 'it']:
-            return normalized
-        # Default fallback
-        return "de"
+        return normalizePrimaryLanguageTag(normalized, "de")
     
     enabled: bool = Field(
         default=True,
diff --git a/modules/datamodels/datamodelUtils.py b/modules/datamodels/datamodelUtils.py
index e9b519d4..bdef6cb2 100644
--- a/modules/datamodels/datamodelUtils.py
+++ b/modules/datamodels/datamodelUtils.py
@@ -2,8 +2,9 @@
 # All rights reserved.
 """Utility datamodels: Prompt, TextMultilingual."""
 
-import re as _re
-from typing import Any, Dict, Optional
+import json
+from typing import Any, Dict
+
 from pydantic import BaseModel, Field, field_validator
 from modules.datamodels.datamodelBase import PowerOnModel
 from modules.shared.i18nRegistry import i18nModel
@@ -98,21 +99,6 @@ class TextMultilingual(BaseModel):
         return cls(xx=t)
 
 
-_REPR_PATTERN = _re.compile(r"(\w+)='([^']*)'")
-
-
-def _parseReprString(s: str) -> Optional[Dict[str, str]]:
-    """Parse a Pydantic repr string like "en='text' de=None fr=" into a dict."""
-    matches = _REPR_PATTERN.findall(s)
-    if not matches:
-        return None
-    result = {}
-    for code, text in matches:
-        if len(code) <= 5 and text:
-            result[code] = text
-    return result if result else None
-
-
 def coerce_text_multilingual(val: Any) -> TextMultilingual:
     """Normalize str, dict, or TextMultilingual into a valid TextMultilingual instance."""
     if isinstance(val, TextMultilingual):
@@ -125,10 +111,13 @@ def coerce_text_multilingual(val: Any) -> TextMultilingual:
             cleaned["xx"] = cleaned.get("de") or next((v for v in cleaned.values() if v), "—")
         return TextMultilingual(**cleaned)
     if isinstance(val, str) and val.strip():
-        parsed = _parseReprString(val)
-        if parsed:
-            if not parsed.get("xx"):
-                parsed["xx"] = parsed.get("de") or next((v for v in parsed.values() if v), val.strip())
-            return TextMultilingual(**parsed)
-        return TextMultilingual.fromUniform(val)
+        s = val.strip()
+        if s.startswith("{") and s.endswith("}"):
+            try:
+                parsed = json.loads(s)
+                if isinstance(parsed, dict):
+                    return coerce_text_multilingual(parsed)
+            except json.JSONDecodeError:
+                pass
+        return TextMultilingual.fromUniform(s)
     return TextMultilingual.fromUniform("—")
diff --git a/modules/features/chatbot/mainChatbot.py b/modules/features/chatbot/mainChatbot.py
index 79f970c6..b50fef79 100644
--- a/modules/features/chatbot/mainChatbot.py
+++ b/modules/features/chatbot/mainChatbot.py
@@ -191,8 +191,8 @@ def getChatStreamingHelper():
 
 def __get_placeholder_user():
     """Placeholder user for contexts that only need service resolution (e.g. ChatStreamingHelper)."""
-    from modules.datamodels.datamodelUam import User
-    return User(id="system", username="system", email=None, fullName="System Placeholder")
+    from modules.interfaces.interfaceDbApp import getRootInterface
+    return getRootInterface().currentUser
 
 
 def getEventManager(user, mandateId: Optional[str] = None, featureInstanceId: Optional[str] = None):
diff --git a/modules/features/commcoach/interfaceFeatureCommcoach.py b/modules/features/commcoach/interfaceFeatureCommcoach.py
index d4faa18d..c9b4564e 100644
--- a/modules/features/commcoach/interfaceFeatureCommcoach.py
+++ b/modules/features/commcoach/interfaceFeatureCommcoach.py
@@ -13,7 +13,7 @@ from modules.datamodels.datamodelUam import User
 from modules.connectors.connectorDbPostgre import DatabaseConnector
 from modules.shared.timeUtils import getIsoTimestamp
 from modules.shared.configuration import APP_CONFIG
-from modules.shared.i18nRegistry import t
+from modules.shared.i18nRegistry import resolveText, t
 
 from .datamodelCommcoach import (
     CoachingContext, CoachingContextStatus,
@@ -414,16 +414,20 @@ def _calcGoalProgress(goalsRaw) -> Optional[int]:
 
 
 _LEVELS = [
-    (50, 5, "master", t("Meister")),
-    (25, 4, "expert", t("Experte")),
-    (10, 3, "advanced", t("Fortgeschritten")),
-    (3,  2, "engaged", t("Engagiert")),
+    (50, 5, "master", "Meister"),
+    (25, 4, "expert", "Experte"),
+    (10, 3, "advanced", "Fortgeschritten"),
+    (3,  2, "engaged", "Engagiert"),
 ]
+t("Meister")
+t("Experte")
+t("Fortgeschritten")
+t("Engagiert")
 t("Einsteiger")
 
 
 def _calcLevel(totalSessions: int) -> Dict[str, Any]:
-    for threshold, number, code, _label in _LEVELS:
+    for threshold, number, code, labelKey in _LEVELS:
         if totalSessions >= threshold:
-            return {"number": number, "code": code, "label": t(_label), "totalSessions": totalSessions}
-    return {"number": 1, "code": "beginner", "label": t("Einsteiger"), "totalSessions": totalSessions}
+            return {"number": number, "code": code, "label": resolveText(labelKey), "totalSessions": totalSessions}
+    return {"number": 1, "code": "beginner", "label": resolveText("Einsteiger"), "totalSessions": totalSessions}
diff --git a/modules/features/commcoach/mainCommcoach.py b/modules/features/commcoach/mainCommcoach.py
index 90789ec6..acbd62a6 100644
--- a/modules/features/commcoach/mainCommcoach.py
+++ b/modules/features/commcoach/mainCommcoach.py
@@ -236,9 +236,9 @@ def _seedBuiltinPersonas():
     try:
         from .serviceCommcoachPersonas import seedBuiltinPersonas
         from .interfaceFeatureCommcoach import getInterface
-        from modules.datamodels.datamodelUam import User
+        from modules.interfaces.interfaceDbApp import getRootInterface
 
-        systemUser = User(id="system", username="system", email="system@poweron.swiss")
+        systemUser = getRootInterface().currentUser
         interface = getInterface(systemUser)
         seedBuiltinPersonas(interface)
     except Exception as e:
diff --git a/modules/features/commcoach/serviceCommcoachGamification.py b/modules/features/commcoach/serviceCommcoachGamification.py
index 5aa796b7..180706de 100644
--- a/modules/features/commcoach/serviceCommcoachGamification.py
+++ b/modules/features/commcoach/serviceCommcoachGamification.py
@@ -7,7 +7,7 @@ Checks and awards badges after each session completion.
 
 import logging
 from typing import Dict, Any, List, Optional
-from modules.shared.i18nRegistry import t
+from modules.shared.i18nRegistry import resolveText, t
 
 logger = logging.getLogger(__name__)
 
@@ -80,9 +80,32 @@ BADGE_DEFINITIONS: Dict[str, Dict[str, Any]] = {
 }
 
 # Register all badge labels/descriptions at import time for i18n xx base set
-for _bd in BADGE_DEFINITIONS.values():
-    t(_bd["label"])
-    t(_bd["description"])
+t("Erste Session")
+t("Deine erste Coaching-Session abgeschlossen")
+t("3-Tage-Serie")
+t("3 Tage in Folge eine Session absolviert")
+t("Wochenserie")
+t("7 Tage in Folge eine Session absolviert")
+t("Monatsserie")
+t("30 Tage in Folge eine Session absolviert")
+t("Engagiert")
+t("5 Sessions abgeschlossen")
+t("Fortgeschritten")
+t("10 Sessions abgeschlossen")
+t("Experte")
+t("25 Sessions abgeschlossen")
+t("Meister")
+t("50 Sessions abgeschlossen")
+t("Bestleistung")
+t("Durchschnittsscore über 80 in einer Session")
+t("Vielseitig")
+t("3 verschiedene Coaching-Themen aktiv")
+t("Rollenspieler")
+t("Erste Roleplay-Session mit einer Persona abgeschlossen")
+t("Ganzheitlich")
+t("In allen 5 Kompetenz-Dimensionen bewertet")
+t("Umsetzer")
+t("10 Coaching-Aufgaben erledigt")
 
 
 async def checkAndAwardBadges(interface, userId: str, mandateId: str, instanceId: str,
@@ -141,8 +164,8 @@ async def checkAndAwardBadges(interface, userId: str, mandateId: str, instanceId
             }
             newBadge = interface.awardBadge(badgeData)
             definition = BADGE_DEFINITIONS.get(badgeKey, {})
-            newBadge["label"] = t(definition.get("label", badgeKey))
-            newBadge["description"] = t(definition.get("description", ""))
+            newBadge["label"] = resolveText(definition.get("label", badgeKey))
+            newBadge["description"] = resolveText(definition.get("description", ""))
             newBadge["icon"] = definition.get("icon", "star")
             awarded.append(newBadge)
             logger.info(f"Badge '{badgeKey}' awarded to user {userId}")
@@ -154,5 +177,9 @@ def getBadgeDefinitions() -> Dict[str, Dict[str, Any]]:
     """Return all badge definitions for the frontend (labels resolved via i18n)."""
     resolved = {}
     for key, defn in BADGE_DEFINITIONS.items():
-        resolved[key] = {**defn, "label": t(defn["label"]), "description": t(defn["description"])}
+        resolved[key] = {
+            **defn,
+            "label": resolveText(defn["label"]),
+            "description": resolveText(defn["description"]),
+        }
     return resolved
diff --git a/modules/features/graphicalEditor/entryPoints.py b/modules/features/graphicalEditor/entryPoints.py
index c63ada70..9ade2e96 100644
--- a/modules/features/graphicalEditor/entryPoints.py
+++ b/modules/features/graphicalEditor/entryPoints.py
@@ -36,10 +36,11 @@ def default_manual_entry_point() -> Dict[str, Any]:
     }
 
 
-def _normalize_title(title: Any, preferredLang: Optional[str] = None) -> str:
+def _normalize_title(title: Any) -> str:
+    """Extract a plain string from a title value for storage (not display)."""
     if isinstance(title, dict):
-        picked = (preferredLang and title.get(preferredLang)) or title.get("xx") or next(iter(title.values()), "")
-        return str(picked).strip() if picked is not None else ""
+        picked = title.get("xx") or next((v for v in title.values() if v), None)
+        return str(picked).strip() if picked else "Start"
     if isinstance(title, str) and title.strip():
         return title.strip()
     return "Start"
diff --git a/modules/features/graphicalEditor/nodeRegistry.py b/modules/features/graphicalEditor/nodeRegistry.py
index 81cce9c7..1af0beb7 100644
--- a/modules/features/graphicalEditor/nodeRegistry.py
+++ b/modules/features/graphicalEditor/nodeRegistry.py
@@ -10,13 +10,14 @@ from typing import Dict, List, Any
 
 from modules.features.graphicalEditor.nodeDefinitions import STATIC_NODE_TYPES
 from modules.features.graphicalEditor.portTypes import PORT_TYPE_CATALOG, SYSTEM_VARIABLES
+from modules.shared.i18nRegistry import normalizePrimaryLanguageTag
 
 logger = logging.getLogger(__name__)
 
 
 def getNodeTypes(
     services: Any = None,
-    language: str = "en",
+    language: str = "de",
 ) -> List[Dict[str, Any]]:
     """
     Return static node types. No dynamic I/O derivation from methodDiscovery.
@@ -25,27 +26,42 @@ def getNodeTypes(
     return list(STATIC_NODE_TYPES)
 
 
+def _pickFromLangMap(d: Any, lang: str) -> Any:
+    """Resolve multilingual dict: ``lang`` → ``xx`` → ``de`` → ``en`` → first non-empty value."""
+    if not isinstance(d, dict) or not d:
+        return None
+    for k in (lang, "xx", "de", "en"):
+        v = d.get(k)
+        if v is not None and v != "":
+            return v
+    for v in d.values():
+        if v is not None and v != "":
+            return v
+    return None
+
+
 def _localizeNode(node: Dict[str, Any], language: str) -> Dict[str, Any]:
     """Apply language to label/description/parameters. Keep inputPorts/outputPorts."""
-    lang = language if language in ("en", "de", "fr") else "en"
+    lang = normalizePrimaryLanguageTag(language, "en")
     out = dict(node)
     for key in list(out.keys()):
         if key.startswith("_"):
             del out[key]
     if isinstance(node.get("label"), dict):
-        out["label"] = node["label"].get(lang, node["label"].get("en", str(node["label"])))
+        out["label"] = _pickFromLangMap(node["label"], lang) or node.get("id", "")
     if isinstance(node.get("description"), dict):
-        out["description"] = node["description"].get(lang, node["description"].get("en", str(node["description"])))
+        out["description"] = _pickFromLangMap(node["description"], lang) or ""
     ol = node.get("outputLabels")
     if isinstance(ol, dict) and ol:
         first = next(iter(ol.values()), None)
         if isinstance(first, (list, tuple)):
-            out["outputLabels"] = ol.get(lang, ol.get("en", list(first)))
+            picked = _pickFromLangMap(ol, lang)
+            out["outputLabels"] = picked if picked is not None else list(first)
     params = []
     for p in node.get("parameters", []):
         pc = dict(p)
         if isinstance(p.get("description"), dict):
-            pc["description"] = p["description"].get(lang, p["description"].get("en", str(p.get("description", ""))))
+            pc["description"] = _pickFromLangMap(p["description"], lang) or str(p.get("description", ""))
         params.append(pc)
     out["parameters"] = params
     return out
@@ -53,7 +69,7 @@ def _localizeNode(node: Dict[str, Any], language: str) -> Dict[str, Any]:
 
 def getNodeTypesForApi(
     services: Any,
-    language: str = "en",
+    language: str = "de",
 ) -> Dict[str, Any]:
     """
     API-ready response: nodeTypes with localized strings, plus categories, portTypeCatalog, systemVariables.
diff --git a/modules/features/graphicalEditor/portTypes.py b/modules/features/graphicalEditor/portTypes.py
index c7d6e1dd..d9ae2792 100644
--- a/modules/features/graphicalEditor/portTypes.py
+++ b/modules/features/graphicalEditor/portTypes.py
@@ -14,6 +14,8 @@ from typing import Any, Callable, Dict, List, Optional
 
 from pydantic import BaseModel, Field
 
+from modules.shared.i18nRegistry import resolveText
+
 logger = logging.getLogger(__name__)
 
 
@@ -480,11 +482,9 @@ def _deriveFormPayloadSchema(node: Dict[str, Any]) -> Optional[PortSchema]:
     for f in fields_param:
         if isinstance(f, dict) and f.get("name"):
             _lab = f.get("label")
-            _desc = (
-                str(_lab.get("xx") or next(iter(_lab.values()), "") or f["name"])
-                if isinstance(_lab, dict)
-                else str(_lab if _lab is not None else f["name"])
-            )
+            _desc = resolveText(_lab) if _lab is not None else f["name"]
+            if not _desc.strip():
+                _desc = f["name"]
             portFields.append(PortField(
                 name=f["name"],
                 type=f.get("type", "str"),
diff --git a/modules/features/graphicalEditor/routeFeatureGraphicalEditor.py b/modules/features/graphicalEditor/routeFeatureGraphicalEditor.py
index 91c907b5..7f2139e5 100644
--- a/modules/features/graphicalEditor/routeFeatureGraphicalEditor.py
+++ b/modules/features/graphicalEditor/routeFeatureGraphicalEditor.py
@@ -26,21 +26,12 @@ from modules.workflows.automation2.runEnvelope import (
     normalize_run_envelope,
 )
 from modules.features.graphicalEditor.entryPoints import find_invocation
-from modules.shared.i18nRegistry import apiRouteContext
+from modules.shared.i18nRegistry import apiRouteContext, resolveText
 routeApiMsg = apiRouteContext("routeFeatureGraphicalEditor")
 
 logger = logging.getLogger(__name__)
 
 
-def _pickInvocationTitleLabel(title: Any, requestLang: Optional[str]) -> str:
-    if isinstance(title, str):
-        return title
-    if isinstance(title, dict) and title:
-        picked = (requestLang and title.get(requestLang)) or title.get("xx") or next(iter(title.values()), "")
-        return str(picked) if picked else ""
-    return ""
-
-
 def _build_execute_run_envelope(
     body: Dict[str, Any],
     workflow: Optional[Dict[str, Any]],
@@ -80,7 +71,7 @@ def _build_execute_run_envelope(
         }
         trig = trig_map.get(kind, "manual")
         title = inv.get("title") or {}
-        label = _pickInvocationTitleLabel(title, requestLang)
+        label = resolveText(title)
         base = default_run_envelope(
             trig,
             entry_point_id=inv.get("id"),
@@ -1052,10 +1043,7 @@ async def post_workflow_webhook(
     discoverMethods(services)
 
     title = inv.get("title") or {}
-    label = _pickInvocationTitleLabel(
-        title,
-        getattr(context.user, "language", None) if context.user else None,
-    )
+    label = resolveText(title)
     pl = body if isinstance(body, dict) else {}
     base = default_run_envelope(
         "webhook",
@@ -1113,10 +1101,7 @@ async def post_workflow_form_submit(
     discoverMethods(services)
 
     title = inv.get("title") or {}
-    label = _pickInvocationTitleLabel(
-        title,
-        getattr(context.user, "language", None) if context.user else None,
-    )
+    label = resolveText(title)
     pl = body if isinstance(body, dict) else {}
     base = default_run_envelope(
         "form",
diff --git a/modules/features/teamsbot/routeFeatureTeamsbot.py b/modules/features/teamsbot/routeFeatureTeamsbot.py
index c2823a85..d316bde2 100644
--- a/modules/features/teamsbot/routeFeatureTeamsbot.py
+++ b/modules/features/teamsbot/routeFeatureTeamsbot.py
@@ -1252,18 +1252,16 @@ async def postTranscript(
         config = _getInstanceConfig(instanceId)
 
         # Load original user context from session
-        from modules.datamodels.datamodelUam import User
-
-        systemUser = User(id="system", username="system", email="system@poweron.swiss")
-        sessionInterface = interfaceDb.getInterface(systemUser, featureInstanceId=instanceId)
+        rootInterface = getRootInterface()
+        rootUser = rootInterface.currentUser
+        sessionInterface = interfaceDb.getInterface(rootUser, featureInstanceId=instanceId)
         session = sessionInterface.getSession(sessionId)
         mandateId = session.get("mandateId") if session else None
         startedByUserId = session.get("startedByUserId") if session else None
 
-        rootInterface = getRootInterface()
         originalUser = rootInterface.getUser(startedByUserId) if startedByUserId else None
         if not originalUser:
-            originalUser = systemUser
+            originalUser = rootUser
 
         # Process transcript through the service pipeline
         from .service import TeamsbotService
@@ -1308,18 +1306,16 @@ async def postBotStatus(
     try:
         config = _getInstanceConfig(instanceId)
 
-        from modules.datamodels.datamodelUam import User
-
-        systemUser = User(id="system", username="system", email="system@poweron.swiss")
-        sessionInterface = interfaceDb.getInterface(systemUser, featureInstanceId=instanceId)
+        rootInterface = getRootInterface()
+        rootUser = rootInterface.currentUser
+        sessionInterface = interfaceDb.getInterface(rootUser, featureInstanceId=instanceId)
         session = sessionInterface.getSession(sessionId)
         mandateId = session.get("mandateId") if session else None
         startedByUserId = session.get("startedByUserId") if session else None
 
-        rootInterface = getRootInterface()
         originalUser = rootInterface.getUser(startedByUserId) if startedByUserId else None
         if not originalUser:
-            originalUser = systemUser
+            originalUser = rootUser
 
         from .service import TeamsbotService
         service = TeamsbotService(originalUser, mandateId, instanceId, config)
@@ -1361,22 +1357,20 @@ async def botWebsocket(
         
         # Load the original user who started the session (has RBAC roles in mandate)
         # Bot callbacks have no HTTP auth, so we reconstruct the user context from the session record.
-        from modules.datamodels.datamodelUam import User
         from modules.interfaces.interfaceDbApp import getRootInterface
         
-        systemUser = User(id="system", username="system", email="system@poweron.swiss")
-        sessionInterface = interfaceDb.getInterface(systemUser, featureInstanceId=instanceId)
+        rootInterface = getRootInterface()
+        rootUser = rootInterface.currentUser
+        sessionInterface = interfaceDb.getInterface(rootUser, featureInstanceId=instanceId)
         session = sessionInterface.getSession(sessionId)
         mandateId = session.get("mandateId") if session else None
         startedByUserId = session.get("startedByUserId") if session else None
         
-        # Look up the original user (getRootInterface uses admin context, can load any user)
-        rootInterface = getRootInterface()
         originalUser = rootInterface.getUser(startedByUserId) if startedByUserId else None
         
         if not originalUser:
-            logger.warning(f"Could not load original user {startedByUserId}, falling back to system user")
-            originalUser = systemUser
+            logger.warning(f"Could not load original user {startedByUserId}, falling back to root user")
+            originalUser = rootUser
         
         # Build effective config with the session's actual bot name.
         # The session stores the resolved bot name (from system bot or user override).
diff --git a/modules/features/trustee/accounting/accountingRegistry.py b/modules/features/trustee/accounting/accountingRegistry.py
index 707d8fbb..b5ce6e80 100644
--- a/modules/features/trustee/accounting/accountingRegistry.py
+++ b/modules/features/trustee/accounting/accountingRegistry.py
@@ -10,7 +10,7 @@ import os
 from typing import Dict, List, Optional
 
 from .accountingConnectorBase import BaseAccountingConnector
-from modules.shared.i18nRegistry import t
+from modules.shared.i18nRegistry import resolveText
 
 logger = logging.getLogger(__name__)
 
@@ -62,11 +62,11 @@ class AccountingRegistry:
             fields = []
             for f in connector.getRequiredConfigFields():
                 fd = f.model_dump()
-                fd["label"] = t(f.label)
+                fd["label"] = resolveText(f.label)
                 fields.append(fd)
             result.append({
                 "connectorType": connectorType,
-                "label": t(connector.getConnectorLabel()),
+                "label": resolveText(connector.getConnectorLabel()),
                 "configFields": fields,
             })
         return result
diff --git a/modules/features/trustee/routeFeatureTrustee.py b/modules/features/trustee/routeFeatureTrustee.py
index 91de0b60..3233523b 100644
--- a/modules/features/trustee/routeFeatureTrustee.py
+++ b/modules/features/trustee/routeFeatureTrustee.py
@@ -151,12 +151,7 @@ def getQuickActions(
                     if role and role.roleLabel:
                         userRoleLabels.add(role.roleLabel)
 
-    def _resolveText(multilingual, lang: str) -> str:
-        if isinstance(multilingual, str):
-            return multilingual
-        if isinstance(multilingual, dict):
-            return multilingual.get(lang) or multilingual.get("xx") or next(iter(multilingual.values()), "")
-        return ""
+    from modules.shared.i18nRegistry import resolveText
 
     filteredActions = []
     for action in QUICK_ACTIONS:
@@ -166,8 +161,8 @@ def getQuickActions(
         if context.hasSysAdminRole or required.intersection(userRoleLabels):
             resolved = {
                 "id": action["id"],
-                "label": _resolveText(action.get("label", {}), language),
-                "description": _resolveText(action.get("description", {}), language),
+                "label": resolveText(action.get("label", {})),
+                "description": resolveText(action.get("description", {})),
                 "icon": action.get("icon", ""),
                 "color": action.get("color", ""),
                 "category": action.get("category", ""),
@@ -178,14 +173,14 @@ def getQuickActions(
             if resolved["actionType"] == "agentPrompt" and "config" in resolved:
                 cfg = dict(resolved["config"])
                 if "uploadHint" in cfg:
-                    cfg["uploadHint"] = _resolveText(cfg["uploadHint"], language)
+                    cfg["uploadHint"] = resolveText(cfg["uploadHint"])
                 resolved["config"] = cfg
             filteredActions.append(resolved)
 
     filteredActions.sort(key=lambda a: a["sortOrder"])
 
     resolvedCategories = [
-        {"id": c["id"], "label": _resolveText(c.get("label", {}), language), "sortOrder": c.get("sortOrder", 99)}
+        {"id": c["id"], "label": resolveText(c.get("label", {})), "sortOrder": c.get("sortOrder", 99)}
         for c in QUICK_ACTION_CATEGORIES
     ]
 
diff --git a/modules/features/workspace/routeFeatureWorkspace.py b/modules/features/workspace/routeFeatureWorkspace.py
index 16235cd3..08216e56 100644
--- a/modules/features/workspace/routeFeatureWorkspace.py
+++ b/modules/features/workspace/routeFeatureWorkspace.py
@@ -29,7 +29,7 @@ from modules.interfaces.interfaceAiObjects import AiObjects
 from modules.serviceCenter.core.serviceStreaming import get_event_manager
 from modules.serviceCenter.services.serviceAgent.datamodelAgent import AgentEventTypeEnum, PendingFileEdit
 from modules.shared.timeUtils import parseTimestamp
-from modules.shared.i18nRegistry import apiRouteContext, t
+from modules.shared.i18nRegistry import apiRouteContext, resolveText
 routeApiMsg = apiRouteContext("routeFeatureWorkspace")
 
 logger = logging.getLogger(__name__)
@@ -1467,7 +1467,7 @@ async def listFeatureConnectionTables(
         node = {
             "objectKey": obj.get("objectKey", ""),
             "tableName": meta.get("table", ""),
-            "label": t(obj.get("label", "")),
+            "label": resolveText(obj.get("label", "")),
             "fields": meta.get("fields", []),
         }
         if meta.get("isParent"):
diff --git a/modules/interfaces/interfaceDbApp.py b/modules/interfaces/interfaceDbApp.py
index 7e0dd234..d4cb5b08 100644
--- a/modules/interfaces/interfaceDbApp.py
+++ b/modules/interfaces/interfaceDbApp.py
@@ -666,7 +666,7 @@ class AppObjects:
         password: str = None,
         email: str = None,
         fullName: str = None,
-        language: str = "en",
+        language: str = "de",
         enabled: bool = True,
         authenticationAuthority: AuthAuthority = AuthAuthority.LOCAL,
         externalId: str = None,
diff --git a/modules/interfaces/interfaceFeatures.py b/modules/interfaces/interfaceFeatures.py
index bb9ead89..943acdb5 100644
--- a/modules/interfaces/interfaceFeatures.py
+++ b/modules/interfaces/interfaceFeatures.py
@@ -17,6 +17,7 @@ from modules.datamodels.datamodelFeatures import Feature, FeatureInstance
 from modules.datamodels.datamodelRbac import Role, AccessRule
 from modules.datamodels.datamodelUtils import coerce_text_multilingual
 from modules.connectors.connectorDbPostgre import DatabaseConnector
+from modules.shared.i18nRegistry import resolveText
 
 logger = logging.getLogger(__name__)
 
@@ -241,9 +242,9 @@ class FeatureInterface:
                 return 0
 
             from modules.features.graphicalEditor.interfaceFeatureGraphicalEditor import getGraphicalEditorInterface
-            from modules.auth.authModels import SystemUser
-            systemUser = SystemUser()
-            geInterface = getGraphicalEditorInterface(systemUser, mandateId, instanceId)
+            from modules.interfaces.interfaceDbApp import getRootInterface
+            rootUser = getRootInterface().currentUser
+            geInterface = getGraphicalEditorInterface(rootUser, mandateId, instanceId)
 
             copied = 0
             for template in templateWorkflows:
@@ -251,11 +252,7 @@ class FeatureInterface:
                 graphJson = graphJson.replace("{{featureInstanceId}}", instanceId)
                 graph = json.loads(graphJson)
 
-                labelDict = template.get("label", {})
-                if isinstance(labelDict, dict):
-                    label = labelDict.get("xx") or next(iter(labelDict.values()), "") or str(labelDict)
-                else:
-                    label = str(labelDict)
+                label = resolveText(template.get("label"))
 
                 geInterface.createWorkflow({
                     "label": label,
diff --git a/modules/routes/routeAdminFeatures.py b/modules/routes/routeAdminFeatures.py
index 13b47c28..37118426 100644
--- a/modules/routes/routeAdminFeatures.py
+++ b/modules/routes/routeAdminFeatures.py
@@ -27,24 +27,12 @@ from modules.interfaces.interfaceDbApp import getRootInterface
 from modules.interfaces.interfaceFeatures import getFeatureInterface
 from modules.security.rbacCatalog import getCatalogService
 from modules.routes.routeNotifications import create_access_change_notification
-from modules.shared.i18nRegistry import apiRouteContext
+from modules.shared.i18nRegistry import apiRouteContext, resolveText
 routeApiMsg = apiRouteContext("routeAdminFeatures")
 
 logger = logging.getLogger(__name__)
 
 
-def _featureLabelPlain(label: Union[str, Dict[str, str], None], fallback: str, requestLang: Optional[str] = None) -> str:
-    """Catalog feature label as a single display/i18n key string."""
-    if isinstance(label, str) and label.strip():
-        return label
-    if isinstance(label, dict):
-        picked = (requestLang and label.get(requestLang)) or label.get("xx") or next(iter(label.values()), "")
-        if picked:
-            return str(picked)
-        return fallback
-    return fallback
-
-
 def _feature_instance_display_name(instance: Any) -> str:
     if instance is None:
         return ""
@@ -197,11 +185,7 @@ def get_my_feature_instances(
                 featureDef = catalogService.getFeatureDefinition(instance.featureCode)
                 featuresMap[featureKey] = {
                     "code": instance.featureCode,
-                    "label": _featureLabelPlain(
-                        featureDef.get("label") if featureDef else None,
-                        instance.featureCode,
-                        getattr(context.user, "language", None),
-                    ),
+                    "label": resolveText(featureDef.get("label") if featureDef else None),
                     "icon": featureDef.get("icon", "folder") if featureDef else "folder",
                     "instances": [],
                     "_mandateId": mandateId  # Temporary for grouping
diff --git a/modules/routes/routeAdminRbacRules.py b/modules/routes/routeAdminRbacRules.py
index 92ceaf18..9b756152 100644
--- a/modules/routes/routeAdminRbacRules.py
+++ b/modules/routes/routeAdminRbacRules.py
@@ -23,23 +23,12 @@ from modules.datamodels.datamodelRbac import AccessRuleContext, AccessRule, Role
 from modules.datamodels.datamodelMembership import UserMandate
 from modules.datamodels.datamodelPagination import PaginationParams, PaginatedResponse, PaginationMetadata, normalize_pagination_dict
 from modules.interfaces.interfaceDbApp import getInterface, getRootInterface
-from modules.shared.i18nRegistry import apiRouteContext, t, _getLanguage
+from modules.shared.i18nRegistry import apiRouteContext, t, resolveText
 routeApiMsg = apiRouteContext("routeAdminRbacRules")
 
 # Configure logger
 logger = logging.getLogger(__name__)
 
-
-def _resolveTextMultilingual(value) -> str:
-    """Resolve a TextMultilingual dict to a single string for the current request language.
-    Falls back to xx (source text), then any available value."""
-    if isinstance(value, str):
-        return value
-    if isinstance(value, dict):
-        lang = _getLanguage()
-        return value.get(lang) or value.get("xx") or next(iter(value.values()), "")
-    return str(value) if value else ""
-
 router = APIRouter(
     prefix="/api/rbac",
     tags=["RBAC"],
@@ -922,7 +911,7 @@ def list_roles(
             result.append({
                 "id": role.id,
                 "roleLabel": role.roleLabel,
-                "description": _resolveTextMultilingual(role.description),
+                "description": resolveText(role.description),
                 "mandateId": role.mandateId,
                 "featureInstanceId": role.featureInstanceId,
                 "featureCode": role.featureCode,
@@ -1051,7 +1040,7 @@ def get_roles_filter_values(
             result.append({
                 "id": role.id,
                 "roleLabel": role.roleLabel,
-                "description": _resolveTextMultilingual(role.description),
+                "description": resolveText(role.description),
                 "mandateId": role.mandateId,
                 "featureInstanceId": role.featureInstanceId,
                 "featureCode": role.featureCode,
@@ -1168,7 +1157,7 @@ def get_role(
         return {
             "id": role.id,
             "roleLabel": role.roleLabel,
-            "description": _resolveTextMultilingual(role.description),
+            "description": resolveText(role.description),
             "mandateId": role.mandateId,
             "featureInstanceId": role.featureInstanceId,
             "featureCode": role.featureCode,
@@ -1369,12 +1358,8 @@ def getCatalogObjects(
         
         def _resolveLabels(objects: list) -> list:
             for obj in objects:
-                raw = obj.get("label")
-                if isinstance(raw, str):
-                    obj["label"] = t(raw)
-                elif isinstance(raw, dict):
-                    key = raw.get("xx") or next(iter(raw.values()), "") or obj.get("objectKey", "")
-                    obj["label"] = t(key) if key else f"[{obj.get('objectKey', '?')}]"
+                resolved = resolveText(obj.get("label"))
+                obj["label"] = resolved if resolved else f"[{obj.get('objectKey', '?')}]"
             return objects
 
         if context:
diff --git a/modules/routes/routeAdminUserAccessOverview.py b/modules/routes/routeAdminUserAccessOverview.py
index 4b5e1212..59bf415f 100644
--- a/modules/routes/routeAdminUserAccessOverview.py
+++ b/modules/routes/routeAdminUserAccessOverview.py
@@ -24,24 +24,13 @@ from modules.datamodels.datamodelMembership import (
 )
 from modules.datamodels.datamodelFeatures import FeatureInstance, Feature
 from modules.interfaces.interfaceDbApp import getRootInterface
-from modules.shared.i18nRegistry import apiRouteContext, t, _getLanguage
+from modules.shared.i18nRegistry import apiRouteContext, t, resolveText
 routeApiMsg = apiRouteContext("routeAdminUserAccessOverview")
 
 # Configure logger
 logger = logging.getLogger(__name__)
 
 
-def _resolveTextMultilingual(value) -> str:
-    """Resolve a TextMultilingual dict to a single string for the current request language.
-    Falls back to xx (source text), then any available value."""
-    if isinstance(value, str):
-        return value
-    if isinstance(value, dict):
-        lang = _getLanguage()
-        return value.get(lang) or value.get("xx") or next(iter(value.values()), "")
-    return str(value) if value else ""
-
-
 router = APIRouter(
     prefix="/api/admin/user-access-overview",
     tags=["Admin User Access Overview"],
@@ -309,7 +298,7 @@ def getUserAccessOverview(
                         roleInfo = {
                             "id": roleId,
                             "roleLabel": role.roleLabel,
-                            "description": _resolveTextMultilingual(role.description),
+                            "description": resolveText(role.description),
                             "scope": scope,
                             "scopePriority": _getRoleScopePriority(scope),
                             "mandateId": role.mandateId,
@@ -345,7 +334,7 @@ def getUserAccessOverview(
                 # Get feature info using interface method
                 featureCode = instance.featureCode
                 feature = interface.getFeatureByCode(featureCode)
-                featureLabel = t(feature.label) if feature and feature.label else ""
+                featureLabel = resolveText(feature.label) if feature and feature.label else ""
                 
                 # Get roles for this FeatureAccess using interface method
                 instanceRoleIds = interface.getRoleIdsForFeatureAccess(faId)
@@ -359,7 +348,7 @@ def getUserAccessOverview(
                             roleInfo = {
                                 "id": roleId,
                                 "roleLabel": role.roleLabel,
-                            "description": _resolveTextMultilingual(role.description),
+                            "description": resolveText(role.description),
                             "scope": scope,
                             "scopePriority": _getRoleScopePriority(scope),
                             "mandateId": role.mandateId,
diff --git a/modules/routes/routeDataUsers.py b/modules/routes/routeDataUsers.py
index 07c3d81b..28d11392 100644
--- a/modules/routes/routeDataUsers.py
+++ b/modules/routes/routeDataUsers.py
@@ -24,7 +24,7 @@ from modules.auth import limiter, getRequestContext, RequestContext
 from modules.datamodels.datamodelUam import User, UserInDB, AuthAuthority
 from modules.interfaces.interfaceDbApp import getRootInterface
 from modules.datamodels.datamodelPagination import PaginationParams, PaginatedResponse, PaginationMetadata, normalize_pagination_dict
-from modules.shared.i18nRegistry import apiRouteContext
+from modules.shared.i18nRegistry import apiRouteContext, resolveText
 routeApiMsg = apiRouteContext("routeDataUsers")
 
 # Configure logger
@@ -87,9 +87,9 @@ def _extractDistinctValues(
         elif isinstance(val, (int, float)):
             values.add(str(val))
         elif isinstance(val, dict):
-            text = (requestLang and val.get(requestLang)) or val.get("xx") or next(iter(val.values()), None)
+            text = resolveText(val, requestLang)
             if text:
-                values.add(str(text))
+                values.add(text)
         else:
             values.add(str(val))
     return sorted(values, key=lambda v: v.lower())
@@ -606,7 +606,7 @@ class CreateUserRequest(BaseModel):
     username: str
     email: Optional[str] = None
     fullName: Optional[str] = None
-    language: str = "en"
+    language: str = "de"
     enabled: bool = True
     isSysAdmin: bool = False
     password: Optional[str] = None
diff --git a/modules/routes/routeI18n.py b/modules/routes/routeI18n.py
index 070d9c90..41e9645c 100644
--- a/modules/routes/routeI18n.py
+++ b/modules/routes/routeI18n.py
@@ -508,6 +508,24 @@ async def list_language_codes():
     return sorted(out, key=lambda x: (not x.get("isDefault"), x["code"]))
 
 
+@router.get("/user-language-options")
+async def list_user_language_options():
+    """Select options for User.language: all UiLanguageSets except ``xx`` (basis set).
+
+    Returns ``[{ \"value\": code, \"label\": name }, ...]`` for FormGenerator ``frontend_options`` URL.
+    """
+    db = _publicMgmtDb()
+    rows = db.getRecordset(UiLanguageSet)
+    out: List[Dict[str, str]] = []
+    for r in rows:
+        code = r.get("id")
+        if not code or code == "xx":
+            continue
+        lbl = (r.get("label") or "").strip() or code
+        out.append({"value": code, "label": lbl})
+    return sorted(out, key=lambda x: (x.get("label") or x["value"]).lower())
+
+
 @router.get("/sets/{code}")
 async def get_language_set(code: str):
     db = _publicMgmtDb()
diff --git a/modules/routes/routeStore.py b/modules/routes/routeStore.py
index d60bd1df..04517d9b 100644
--- a/modules/routes/routeStore.py
+++ b/modules/routes/routeStore.py
@@ -23,23 +23,11 @@ from modules.interfaces.interfaceFeatures import getFeatureInterface
 from modules.security.rbacCatalog import getCatalogService
 from modules.security.rbac import RbacClass
 from modules.security.rootAccess import getRootDbAppConnector
-from modules.shared.i18nRegistry import apiRouteContext
+from modules.shared.i18nRegistry import apiRouteContext, resolveText
 routeApiMsg = apiRouteContext("routeStore")
 
 logger = logging.getLogger(__name__)
 
-
-def _storeLabelText(label: Union[str, Dict[str, str], None], fallback: str, requestLang: Optional[str] = None) -> str:
-    """Normalize catalog label to a single display/i18n key string."""
-    if isinstance(label, str) and label.strip():
-        return label
-    if isinstance(label, dict):
-        picked = (requestLang and label.get(requestLang)) or label.get("xx") or next(iter(label.values()), "")
-        if picked:
-            return str(picked)
-        return fallback
-    return fallback
-
 router = APIRouter(
     prefix="/api/store",
     tags=["Store"],
@@ -301,9 +289,9 @@ def listStoreFeatures(
             instances = _getUserInstancesForFeature(db, userId, featureCode, userMandateIds)
             result.append(StoreFeatureResponse(
                 featureCode=featureCode,
-                label=_storeLabelText(featureDef.get("label"), featureCode, getattr(context.user, "language", None)),
+                label=resolveText(featureDef.get("label")),
                 icon=featureDef.get("icon", "mdi-puzzle"),
-                description=_storeLabelText(featureDef.get("description"), "", getattr(context.user, "language", None)),
+                description=resolveText(featureDef.get("description")),
                 instances=instances,
                 canActivate=True,
             ))
@@ -391,7 +379,7 @@ def activateStoreFeature(
 
         # ── 3. Provision instance ───────────────────────────────────────
         featureInterface = getFeatureInterface(db)
-        featureLabel = _storeLabelText(featureDef.get("label"), featureCode, getattr(context.user, "language", None))
+        featureLabel = resolveText(featureDef.get("label"))
         instance = featureInterface.createFeatureInstance(
             featureCode=featureCode,
             mandateId=mandateId,
diff --git a/modules/serviceCenter/services/serviceAgent/featureDataAgent.py b/modules/serviceCenter/services/serviceAgent/featureDataAgent.py
index d1726fcd..43dbb9d7 100644
--- a/modules/serviceCenter/services/serviceAgent/featureDataAgent.py
+++ b/modules/serviceCenter/services/serviceAgent/featureDataAgent.py
@@ -21,6 +21,7 @@ from modules.serviceCenter.services.serviceAgent.datamodelAgent import (
 )
 from modules.serviceCenter.services.serviceAgent.toolRegistry import ToolRegistry
 from modules.serviceCenter.services.serviceAgent.featureDataProvider import FeatureDataProvider
+from modules.shared.i18nRegistry import resolveText
 
 logger = logging.getLogger(__name__)
 
@@ -305,12 +306,7 @@ def _buildSchemaContext(
         meta = obj.get("meta", {})
         tbl = meta.get("table", "?")
         fields = meta.get("fields", [])
-        label = obj.get("label", {})
-        if isinstance(label, dict):
-            picked = (requestLang and label.get(requestLang)) or label.get("xx") or next(iter(label.values()), "")
-            labelStr = str(picked) if picked else tbl
-        else:
-            labelStr = str(label).strip() if isinstance(label, str) and str(label).strip() else tbl
+        labelStr = resolveText(obj.get("label"), requestLang)
         tableNames.append(tbl)
         block = f"  Table: {tbl}  ({labelStr})"
         if fields:
diff --git a/modules/serviceCenter/services/serviceAi/subStructureFilling.py b/modules/serviceCenter/services/serviceAi/subStructureFilling.py
index 3795f44d..b31bc32d 100644
--- a/modules/serviceCenter/services/serviceAi/subStructureFilling.py
+++ b/modules/serviceCenter/services/serviceAi/subStructureFilling.py
@@ -2051,7 +2051,7 @@ class StructureFiller:
         contentPartInstructions: Dict[str, Any],
         contentParts: List[ContentPart],
         userPrompt: str,
-        language: str = "en",
+        language: str = "de",
         outputFormat: str = "txt"
     ) -> str:
         """Baue Prompt für Chapter-Sections-Struktur-Generierung, querying renderer for accepted section types."""
@@ -2187,7 +2187,7 @@ Return only valid JSON. Do not include any explanatory text outside the JSON.
         allSections: Optional[List[Dict[str, Any]]] = None,
         sectionIndex: Optional[int] = None,
         isAggregation: bool = False,
-        language: str = "en",
+        language: str = "de",
         outputFormat: str = "txt",
         preExtractedText: Optional[str] = None
     ) -> tuple[str, str]:
diff --git a/modules/serviceCenter/services/serviceAi/subStructureGeneration.py b/modules/serviceCenter/services/serviceAi/subStructureGeneration.py
index 72127c92..3d531756 100644
--- a/modules/serviceCenter/services/serviceAi/subStructureGeneration.py
+++ b/modules/serviceCenter/services/serviceAi/subStructureGeneration.py
@@ -14,6 +14,7 @@ from typing import Dict, Any, List, Optional
 from modules.datamodels.datamodelExtraction import ContentPart
 from modules.datamodels.datamodelAi import AiCallOptions, OperationTypeEnum, PriorityEnum, ProcessingModeEnum
 from modules.workflows.processing.shared.stateTools import checkWorkflowStopped
+from modules.shared.i18nRegistry import normalizePrimaryLanguageTag
 
 logger = logging.getLogger(__name__)
 
@@ -262,18 +263,17 @@ CRITICAL:
                 # Validation 3.5 & 3.6: Document language
                 # Use validated currentUserLanguage (always valid, validated during user intention analysis)
                 # Access via _getUserLanguage() which uses self.services.currentUserLanguage
-                userPromptLanguage = self._getUserLanguage()  # Uses validated currentUserLanguage infrastructure
-                
-                if "language" not in doc or not isinstance(doc["language"], str) or len(doc["language"]) != 2:
-                    # AI didn't return language or invalid format - use validated currentUserLanguage
+                userPromptLanguage = normalizePrimaryLanguageTag(self._getUserLanguage(), "de")
+
+                raw_lang = doc.get("language")
+                if not isinstance(raw_lang, str) or not str(raw_lang).strip():
                     doc["language"] = userPromptLanguage
                     if "language" not in doc:
                         logger.warning(f"Document {doc.get('id')} missing language - using currentUserLanguage: {userPromptLanguage}")
                     else:
-                        logger.warning(f"Document {doc.get('id')} has invalid language format from AI: {doc['language']}, using currentUserLanguage")
+                        logger.warning(f"Document {doc.get('id')} has invalid language format from AI: {doc.get('language')}, using currentUserLanguage")
                 else:
-                    # AI returned valid language format - normalize
-                    doc["language"] = doc["language"].lower().strip()[:2]
+                    doc["language"] = normalizePrimaryLanguageTag(str(raw_lang), userPromptLanguage)
                     logger.debug(f"Document {doc.get('id')} using AI-determined language: {doc['language']}")
                 
                 # Validation 3.7: Document missing 'chapters' field
diff --git a/modules/shared/attributeUtils.py b/modules/shared/attributeUtils.py
index b36addf5..898ca85f 100644
--- a/modules/shared/attributeUtils.py
+++ b/modules/shared/attributeUtils.py
@@ -45,77 +45,53 @@ def _getModelLabelEntry(modelName: str) -> Dict[str, Any]:
     return i18nModelLabels.get(modelName) or {}
 
 
-def getModelLabels(modelName: str, language: str = "en") -> Dict[str, str]:
+def getModelLabels(modelName: str) -> Dict[str, str]:
     """Get labels for a model's attributes in the specified language.
 
-    Reads @i18nModel registration (German base strings); non-German languages use the i18n cache.
-    Attribute values are strings; dict-shaped entries are still accepted for unusual callers.
+    Reads @i18nModel registration (German base strings); resolves via resolveText().
     """
     modelData = _getModelLabelEntry(modelName)
     attributeLabels = modelData.get("attributes", {})
 
+    from modules.shared.i18nRegistry import resolveText
     result: Dict[str, str] = {}
     for attr, translations in attributeLabels.items():
-        if isinstance(translations, dict):
-            germanKey = translations.get("xx") or next(iter(translations.values()), attr)
-            result[attr] = _resolveLabel(germanKey, language)
-        elif isinstance(translations, str):
-            result[attr] = _resolveLabel(translations, language)
-        else:
-            result[attr] = f"[{attr}]"
+        resolved = resolveText(translations)
+        result[attr] = resolved if resolved else f"[{attr}]"
     return result
 
 
-def _resolveLabel(germanText: str, language: str) -> str:
-    """Resolve a German base label to the requested language via i18n cache.
-    Returns [germanText] when no translation exists so missing keys are visible in the UI."""
-    if language == "de":
-        return germanText
-    try:
-        from modules.shared.i18nRegistry import _CACHE
-        return _CACHE.get(language, {}).get(germanText, f"[{germanText}]")
-    except ImportError:
-        return germanText
-
-
-def _resolveOptionLabels(options, userLanguage: str):
-    """Resolve frontend_options label values to the requested language."""
+def _resolveOptionLabels(options):
+    """Resolve frontend_options label values via resolveText()."""
     if not isinstance(options, list):
         return options
+    from modules.shared.i18nRegistry import resolveText
     for opt in options:
         if not isinstance(opt, dict) or "label" not in opt:
             continue
-        raw = opt["label"]
-        if isinstance(raw, dict):
-            germanKey = raw.get("xx") or next(iter(raw.values()), str(opt.get("value", "")))
-            opt["label"] = _resolveLabel(germanKey, userLanguage)
-        elif isinstance(raw, str):
-            opt["label"] = _resolveLabel(raw, userLanguage)
+        opt["label"] = resolveText(opt["label"])
     return options
 
 
-def _mergedAttributeLabels(modelClass: Type[BaseModel], userLanguage: str) -> Dict[str, str]:
+def _mergedAttributeLabels(modelClass: Type[BaseModel]) -> Dict[str, str]:
     """Merge attribute labels from model MRO (base classes first, subclass overrides)."""
     try:
         baseIdx = modelClass.__mro__.index(BaseModel)
     except ValueError:
-        return getModelLabels(modelClass.__name__, userLanguage)
+        return getModelLabels(modelClass.__name__)
     merged: Dict[str, str] = {}
     for cls in reversed(modelClass.__mro__[:baseIdx]):
-        merged.update(getModelLabels(cls.__name__, userLanguage))
+        merged.update(getModelLabels(cls.__name__))
     return merged
 
 
-def getModelLabel(modelName: str, language: str = "de") -> str:
-    """Get the label for a model in the specified language (see getModelLabels)."""
+def getModelLabel(modelName: str) -> str:
+    """Get the label for a model via resolveText()."""
     modelData = _getModelLabelEntry(modelName)
     modelLabel = modelData.get("model", {})
-    if isinstance(modelLabel, dict):
-        germanKey = modelLabel.get("xx") or next(iter(modelLabel.values()), modelName)
-        return _resolveLabel(germanKey, language)
-    elif isinstance(modelLabel, str):
-        return _resolveLabel(modelLabel, language)
-    return f"[{modelName}]"
+    from modules.shared.i18nRegistry import resolveText
+    resolved = resolveText(modelLabel)
+    return resolved if resolved else f"[{modelName}]"
 
 
 def getModelAttributeDefinitions(modelClass: Type[BaseModel] = None, userLanguage: str = "en") -> Dict[str, Any]:
@@ -134,8 +110,8 @@ def getModelAttributeDefinitions(modelClass: Type[BaseModel] = None, userLanguag
 
     attributes = []
     model_name = modelClass.__name__
-    labels = _mergedAttributeLabels(modelClass, userLanguage)
-    model_label = getModelLabel(model_name, userLanguage)
+    labels = _mergedAttributeLabels(modelClass)
+    model_label = getModelLabel(model_name)
 
     # Pydantic v2 only
     fields = modelClass.model_fields
@@ -273,7 +249,7 @@ def getModelAttributeDefinitions(modelClass: Type[BaseModel] = None, userLanguag
             "visible": frontend_visible,
             "order": len(attributes),
             "readonly": frontend_readonly,
-            "options": _resolveOptionLabels(frontend_options, userLanguage),
+            "options": _resolveOptionLabels(frontend_options),
             "default": field_default,
         }
         
diff --git a/modules/shared/i18nRegistry.py b/modules/shared/i18nRegistry.py
index 7b8c2baf..f681b19f 100644
--- a/modules/shared/i18nRegistry.py
+++ b/modules/shared/i18nRegistry.py
@@ -80,6 +80,50 @@ def t(key: str, context: str = "api", value: str = "") -> str:
     return _CACHE.get(lang, {}).get(key, f"[{key}]")
 
 
+def resolveText(value: Any, lang: Optional[str] = None) -> str:
+    """Resolve any value to a translated string for the current request language.
+
+    Accepts str, dict, TextMultilingual, or None.
+    - str: translate via t() (treats as i18n key / German plaintext key)
+    - dict: multilingual user content — pick ``lang`` (or current context), then ``xx``, then first value
+    - object with model_dump(): convert to dict first (TextMultilingual)
+    - None/empty: return ""
+
+    If ``lang`` is given, it temporarily overrides the context language for this call
+    (used by schedulers that have an explicit user language).
+
+    Missing i18n translations for string keys use t()'s ``[key]`` fallback.
+    """
+    if lang is not None:
+        token = _CURRENT_LANGUAGE.set(lang)
+        try:
+            return _resolveTextImpl(value)
+        finally:
+            _CURRENT_LANGUAGE.reset(token)
+    return _resolveTextImpl(value)
+
+
+def _resolveTextImpl(value: Any) -> str:
+    if value is None:
+        return ""
+    if isinstance(value, str):
+        if not value.strip():
+            return ""
+        return t(value)
+    if hasattr(value, "model_dump"):
+        value = value.model_dump()
+    if isinstance(value, dict):
+        if not value:
+            return ""
+        lang = _CURRENT_LANGUAGE.get()
+        text = value.get(lang) or value.get("xx")
+        if text:
+            return str(text)
+        first = next((v for v in value.values() if v), None)
+        return str(first) if first else ""
+    return str(value)
+
+
 def apiRouteContext(routeModuleName: str):
     """Return a callable that registers + translates HTTPException details.
 
@@ -155,6 +199,23 @@ def _getLanguage() -> str:
     return _CURRENT_LANGUAGE.get()
 
 
+def normalizePrimaryLanguageTag(tag: str, fallback: str = "de") -> str:
+    """Primary language subtag from ``Accept-Language`` or a single BCP47 tag.
+
+    Supports 2-letter (ISO 639-1) and 3-letter (ISO 639-2/3) primaries such as ``gsw``.
+    Strips region/variant: ``de-CH`` → ``de``, ``zh-Hans-CN`` → ``zh``.
+    """
+    if not tag or not isinstance(tag, str):
+        return fallback
+    first = tag.split(",")[0].split(";")[0].strip()
+    if not first:
+        return fallback
+    primary = first.split("-")[0].split("_")[0].lower()
+    if primary.isalpha() and 2 <= len(primary) <= 8:
+        return primary
+    return fallback
+
+
 # ---------------------------------------------------------------------------
 # Boot: scan route files for routeApiMsg("…") calls → register eagerly
 # ---------------------------------------------------------------------------
@@ -270,15 +331,10 @@ def _registerFeatureUiLabels():
             _REGISTRY[fl] = _I18nRegistryEntry(context="nav", value="")
             added += 1
         for uiObj in getattr(mod, "UI_OBJECTS", []) or []:
-            lab = uiObj.get("label")
-            if isinstance(lab, str) and lab and lab not in _REGISTRY:
-                _REGISTRY[lab] = _I18nRegistryEntry(context="nav", value="")
+            base = _extractRegistrySourceText(uiObj.get("label"))
+            if base and base not in _REGISTRY:
+                _REGISTRY[base] = _I18nRegistryEntry(context="nav", value="")
                 added += 1
-            elif isinstance(lab, dict):
-                base = lab.get("xx") or next(iter(lab.values()), "")
-                if base and base not in _REGISTRY:
-                    _REGISTRY[base] = _I18nRegistryEntry(context="nav", value="")
-                    added += 1
     logger.info("i18n feature UI labels: %d new keys (nav context)", added)
 
 
diff --git a/modules/workflows/automation2/subAutomation2Schedule.py b/modules/workflows/automation2/subAutomation2Schedule.py
index 01f1efe8..3f42d8f6 100644
--- a/modules/workflows/automation2/subAutomation2Schedule.py
+++ b/modules/workflows/automation2/subAutomation2Schedule.py
@@ -9,6 +9,7 @@ import logging
 from typing import Any, Dict, Optional
 
 from modules.shared.eventManagement import eventManager
+from modules.shared.i18nRegistry import resolveText
 
 # Main loop reference for scheduling async work from job executor (may run in thread)
 _main_loop = None
@@ -214,13 +215,7 @@ def _create_schedule_handler(
 
             title = (inv or {}).get("title") or {}
             requestLang: Optional[str] = getattr(event_user, "language", None)
-            if isinstance(title, dict):
-                picked = (requestLang and title.get(requestLang)) or title.get("xx") or next(iter(title.values()), "")
-                label = str(picked) if picked else ""
-            elif isinstance(title, str):
-                label = title
-            else:
-                label = ""
+            label = resolveText(title, requestLang) if title else ""
 
             run_env = default_run_envelope(
                 "schedule",
diff --git a/modules/workflows/methods/methodFile/actions/create.py b/modules/workflows/methods/methodFile/actions/create.py
index 73816da0..b9aafcd3 100644
--- a/modules/workflows/methods/methodFile/actions/create.py
+++ b/modules/workflows/methods/methodFile/actions/create.py
@@ -7,6 +7,7 @@ from typing import Dict, Any
 
 from modules.datamodels.datamodelChat import ActionResult, ActionDocument
 from modules.serviceCenter.services.serviceGeneration.subDocumentUtility import markdownToDocumentJson
+from modules.shared.i18nRegistry import normalizePrimaryLanguageTag
 
 logger = logging.getLogger(__name__)
 
@@ -84,7 +85,10 @@ async def create(self, parameters: Dict[str, Any]) -> ActionResult:
     outputFormat = (parameters.get("outputFormat") or "docx").strip().lower().lstrip(".")
     title = (parameters.get("title") or "Document").strip()
     templateName = parameters.get("templateName")
-    language = (parameters.get("language") or "de").strip()[:2]
+    language = normalizePrimaryLanguageTag(
+        str(parameters.get("language") or "de"),
+        "de",
+    )
 
     try:
         structured_content = markdownToDocumentJson(context, title, language)
diff --git a/modules/workflows/scheduler/mainScheduler.py b/modules/workflows/scheduler/mainScheduler.py
index c869bb69..210784a2 100644
--- a/modules/workflows/scheduler/mainScheduler.py
+++ b/modules/workflows/scheduler/mainScheduler.py
@@ -14,6 +14,7 @@ import logging
 from typing import Any, Dict, Optional
 
 from modules.shared.eventManagement import eventManager
+from modules.shared.i18nRegistry import resolveText
 
 logger = logging.getLogger(__name__)
 
@@ -232,13 +233,7 @@ class WorkflowScheduler:
 
                 title = (inv or {}).get("title") or {}
                 requestLang: Optional[str] = getattr(eventUser, "language", None)
-                if isinstance(title, dict):
-                    picked = (requestLang and title.get(requestLang)) or title.get("xx") or next(iter(title.values()), "")
-                    label = str(picked) if picked else ""
-                elif isinstance(title, str):
-                    label = title
-                else:
-                    label = ""
+                label = resolveText(title, requestLang) if title else ""
 
                 runEnv = default_run_envelope(
                     "schedule",