diff --git a/src/components/Dateien/DateienUploadModal.module.css b/src/components/Dateien/DateienUploadModal.module.css
deleted file mode 100644
index e69de29..0000000
diff --git a/src/components/Dateien/DateienUploadModal.tsx b/src/components/Dateien/DateienUploadModal.tsx
deleted file mode 100644
index e69de29..0000000
diff --git a/src/components/FilePreview/FilePreview.module.css b/src/components/FilePreview/FilePreview.module.css
index 085ef17..ce25139 100644
--- a/src/components/FilePreview/FilePreview.module.css
+++ b/src/components/FilePreview/FilePreview.module.css
@@ -305,6 +305,9 @@
   display: flex;
   align-items: flex-start;
   box-sizing: border-box;
+  word-wrap: break-word;
+  white-space: pre-wrap;
+  width: 100%;
 }
 
 .jsonTableValue {
@@ -325,6 +328,9 @@
   background: transparent;
   line-height: 1.4;
   width: 100%;
+  
+  word-wrap: break-word;
+  white-space: -wrap;
 }
 
 .jsonValue {
@@ -347,7 +353,8 @@
     font-weight: 600;
     font-family: 'Fira Code', 'Monaco', 'Cascadia Code', 'Roboto Mono', 'Courier New', monospace;
     font-size: 13px;
-    white-space: nowrap !important;
+    word-wrap: break-word;
+    white-space: pre-wrap;
 }
 
 .jsonValueNumber {
@@ -750,3 +757,85 @@
   }
 }
 
+/* Text Container Styles */
+.textContainer {
+  width: 100%;
+  height: 100%;
+  display: flex;
+  flex-direction: column;
+  background: var(--color-background);
+  border-radius: 8px;
+  overflow: hidden;
+}
+
+.textHeader {
+  padding: 1rem;
+  border-bottom: 1px solid var(--color-border);
+  background: var(--color-background);
+}
+
+.textTitle {
+  font-size: 1.1rem;
+  font-weight: 600;
+  color: var(--color-text);
+  margin-bottom: 0.5rem;
+  display: block;
+}
+
+.warningMessage {
+  display: flex;
+  align-items: center;
+  gap: 0.5rem;
+  padding: 0.75rem;
+  background: var(--color-background);
+  border: 1px solid var(--color-secondary);
+  border-radius: 6px;
+  margin-top: 0.5rem;
+  width: 100%;
+  text-align: center;
+  justify-content: center;
+}
+
+.warningIcon {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  font-size: 1.2rem;
+  color: var(--color-secondary);
+  flex-shrink: 0;
+  margin-top: 0.1rem;
+  text-align: center;
+  justify-content: center;
+}
+
+.warningText {
+  color: var(--color-text);
+  font-size: 0.9rem;
+  line-height: 1.4;
+  font-weight: 500;
+}
+
+.textPreview {
+  flex: 1;
+  padding: 1rem;
+  margin: 0;
+  background: var(--color-background);
+  overflow: auto;
+  font-family: 'Fira Code', 'Monaco', 'Cascadia Code', 'Roboto Mono', 'Courier New', monospace;
+  font-size: 13px;
+  line-height: 1.4;
+  color: var(--color-text);
+  white-space: pre-wrap;
+  word-wrap: break-word;
+}
+
+.textCode {
+  background: transparent;
+  color: var(--color-text);
+  font-family: inherit;
+  font-size: inherit;
+  line-height: inherit;
+  white-space: inherit;
+  word-wrap: inherit;
+}
+
diff --git a/src/components/FilePreview/FilePreview.tsx b/src/components/FilePreview/FilePreview.tsx
index f9ec3c3..32946a8 100644
--- a/src/components/FilePreview/FilePreview.tsx
+++ b/src/components/FilePreview/FilePreview.tsx
@@ -2,7 +2,6 @@ import { useState, useEffect } from 'react';
 
 import { IoIosDownload, IoIosCopy } from 'react-icons/io';
 
-
 import { Popup, PopupAction } from '../Popup/Popup';
 import { useLanguage } from '../../contexts/LanguageContext';
 import { useFileOperations } from '../../hooks/useFiles';
@@ -68,13 +67,16 @@ export function FilePreview({
     try {
       setError(null);
       setPreviewContent(null);
-      const result = await handleFilePreview(fileId, fileName);
+      const result = await handleFilePreview(fileId, fileName, mimeType);
       
-      if (result.success && result.previewUrl) {
-        setPreviewUrl(result.previewUrl);
+      if (result.success) {
+        if (result.previewUrl) {
+          setPreviewUrl(result.previewUrl);
+        }
         if (result.decodedContent) {
           setPreviewContent(result.decodedContent);
         }
+        // If it's text content but MIME type says PDF, we'll handle it in renderPreview
       } else {
         setError(result.error || 'Failed to load preview');
       }
@@ -115,9 +117,12 @@ export function FilePreview({
   const isPreviewing = previewingFiles.has(fileId);
   const hasError = error || previewError;
 
+  // Check if this is a corrupted PDF (text content instead of PDF)
+  const isCorruptedPdf = mimeType === 'application/pdf' && previewContent && !previewUrl;
+
   // Create action buttons for the popup header
   const actions: PopupAction[] = [
-    // Copy Content Button - only show for text-based files (exclude PDFs)
+    // Copy Content Button - only show for text-based files (exclude PDFs) or corrupted PDFs
     ...(mimeType !== 'application/pdf' && (mimeType?.startsWith('text/') || mimeType === 'application/json' || previewContent) ? [{
       label: copySuccess ? t('files.preview.copied', 'Copied!') : t(''),
       icon: copySuccess ? '✓' : <IoIosCopy />,
@@ -126,18 +131,31 @@ export function FilePreview({
       variant: 'primary' as const
     }] : []),
     
-    // Download Button
-    {
+    // Download Button - hide for corrupted PDFs
+    ...(isCorruptedPdf ? [] : [{
       label: String(''),
       icon: downloadingFiles.has(fileId) ? undefined : <IoIosDownload />,
       onClick: handleDownloadFile,
       disabled: downloadingFiles.has(fileId),
       loading: downloadingFiles.has(fileId),
       variant: 'success' as const
-    }
+    }])
   ];
 
   const renderPreview = () => {
+    // Handle text content in PDF files (corrupted files) - check this first
+    if (previewContent && !previewUrl && mimeType === 'application/pdf') {
+      console.log('🔍 FilePreview: Rendering corrupted PDF with text content');
+      return (
+        <PdfRenderer 
+          previewUrl={undefined} 
+          previewContent={previewContent}
+          fileName={fileName} 
+          onError={() => setError('Failed to load PDF preview')}
+        />
+      );
+    }
+
     if (!previewUrl) {
       if (isPreviewing) {
         return <LoadingRenderer />;
@@ -200,9 +218,16 @@ export function FilePreview({
       
       case 'application':
         if (mimeType === 'application/pdf') {
+          console.log('🔍 FilePreview passing normal PDF to PdfRenderer:', {
+            previewUrl,
+            previewContent: previewContent ? `${previewContent.substring(0, 50)}...` : null,
+            fileName,
+            mimeType
+          });
           return (
             <PdfRenderer 
               previewUrl={previewUrl} 
+              previewContent={previewContent || undefined}
               fileName={fileName} 
               onError={() => setError('Failed to load PDF preview')}
             />
diff --git a/src/components/FilePreview/renderers/PdfRenderer.tsx b/src/components/FilePreview/renderers/PdfRenderer.tsx
index bb7b189..ba15ca3 100644
--- a/src/components/FilePreview/renderers/PdfRenderer.tsx
+++ b/src/components/FilePreview/renderers/PdfRenderer.tsx
@@ -1,19 +1,53 @@
+import { IoIosWarning } from 'react-icons/io';
+import { useLanguage } from '../../../contexts/LanguageContext';
 import styles from '../FilePreview.module.css';
 
 interface PdfRendererProps {
-  previewUrl: string;
+  previewUrl?: string;
+  previewContent?: string;
   fileName: string;
   onError: () => void;
 }
 
-export function PdfRenderer({ previewUrl, fileName, onError }: PdfRendererProps) {
+export function PdfRenderer({ previewUrl, previewContent, fileName, onError }: PdfRendererProps) {
+  const { t } = useLanguage();
+
+
+  const handleLoad = () => {
+    console.log('📄 PDF iframe loaded successfully:', { previewUrl, fileName });
+  };
+
+  const handleError = (event: React.SyntheticEvent<HTMLIFrameElement, Event>) => {
+    console.error('❌ PDF iframe failed to load:', { previewUrl, fileName, event });
+    onError();
+  };
+
+  // Handle corrupted PDF files (text content instead of PDF)
+  if (previewContent && !previewUrl) {
+    console.log('📄 Rendering corrupted PDF warning');
+    return (
+      <div className={styles.textContainer}>
+        <div className={styles.textHeader}>
+          <div className={styles.warningMessage}>
+            <span className={styles.warningIcon}><IoIosWarning /></span>
+            <span className={styles.warningText}>
+              {t('files.preview.pdfFileCorrupted', 'This file appears to be corrupted. It has a PDF extension but contains text content. Please re-upload the file if possible.')}
+            </span>
+          </div>
+        </div>
+      </div>
+    );
+  }
+
+  // Normal PDF rendering
   return (
     <iframe
       src={previewUrl}
       className={styles.previewIframe}
       title={`Preview of ${fileName}`}
       data-mime-type="application/pdf"
-      onError={onError}
+      onLoad={handleLoad}
+      onError={handleError}
     />
   );
 }
diff --git a/src/components/FilePreview/renderers/TextRenderer.tsx b/src/components/FilePreview/renderers/TextRenderer.tsx
index 83bf48e..043f780 100644
--- a/src/components/FilePreview/renderers/TextRenderer.tsx
+++ b/src/components/FilePreview/renderers/TextRenderer.tsx
@@ -1,13 +1,33 @@
 import styles from '../FilePreview.module.css';
 
+// Updated to handle both previewUrl and previewContent
+
 interface TextRendererProps {
-  previewUrl: string;
+  previewUrl?: string;
+  previewContent?: string;
   fileName: string;
   mimeType?: string;
   onError: () => void;
 }
 
-export function TextRenderer({ previewUrl, fileName, mimeType, onError }: TextRendererProps) {
+export function TextRenderer({ previewUrl, previewContent, fileName, mimeType, onError }: TextRendererProps) {
+  // If we have previewContent directly, display it as text
+  if (previewContent && !previewUrl) {
+    return (
+      <div className={styles.textContainer}>
+        <div className={styles.textHeader}>
+          <span className={styles.textTitle}>Text Preview</span>
+        </div>
+        <pre className={styles.textPreview}>
+          <code className={styles.textCode}>
+            {previewContent}
+          </code>
+        </pre>
+      </div>
+    );
+  }
+
+  // Otherwise, use iframe with previewUrl
   return (
     <iframe
       src={previewUrl}
diff --git a/src/hooks/useApi.ts b/src/hooks/useApi.ts
index 04fc8ea..2ad3346 100644
--- a/src/hooks/useApi.ts
+++ b/src/hooks/useApi.ts
@@ -60,6 +60,12 @@ export function useApiRequest<RequestData = any, ResponseData = any>() {
         params,
         ...additionalConfig
       });
+      
+      // For blob responses, return the blob data directly
+      if (additionalConfig.responseType === 'blob') {
+        return response.data;
+      }
+      
       return response.data;
     } catch (error: any) {
       const errorMessage = formatApiError(error, `Fehler bei ${method.toUpperCase()} ${url}`);
diff --git a/src/hooks/useFiles.ts b/src/hooks/useFiles.ts
index 9bc4403..900c15a 100644
--- a/src/hooks/useFiles.ts
+++ b/src/hooks/useFiles.ts
@@ -418,14 +418,185 @@ export function useFileOperations() {
     }
   };
 
-  const handleFilePreview = async (fileId: string, fileName: string) => {
+  const handleFilePreview = async (fileId: string, fileName: string, mimeType?: string) => {
     setPreviewError(null);
     setPreviewingFiles(prev => new Set(prev).add(fileId));
     
     try {
-      console.log(`👁️ Starting preview for file: ${fileName} (ID: ${fileId})`);
+      console.log(`👁️ Starting preview for file: ${fileName} (ID: ${fileId})`, { mimeType });
       
-      // First try to get JSON response (for text-based files)
+      // For PDF files, try JSON response first (API returns base64-encoded PDF)
+      if (mimeType === 'application/pdf') {
+        console.log('📄 PDF file detected, trying JSON response with base64 content');
+        
+        try {
+          const jsonResponse = await request({
+            url: `/api/files/${fileId}/preview`,
+            method: 'get',
+            additionalConfig: { 
+              responseType: 'json',
+              validateStatus: function (status: number) {
+                return status >= 200 && status < 300;
+              }
+            }
+          });
+          
+          console.log('📄 PDF JSON response received:', {
+            hasContent: 'content' in jsonResponse,
+            hasMimeType: 'mimeType' in jsonResponse,
+            contentLength: jsonResponse.content?.length,
+            mimeType: jsonResponse.mimeType,
+            contentType: typeof jsonResponse.content,
+            contentStartsWith: jsonResponse.content?.substring(0, 10),
+            fullResponse: jsonResponse
+          });
+          
+          // Check if response has base64-encoded PDF content
+          if (jsonResponse && typeof jsonResponse === 'object' && 'content' in jsonResponse) {
+            let content = jsonResponse.content;
+            const responseMimeType = jsonResponse.mimeType || 'application/pdf';
+            
+            // The content field contains base64-encoded JSON, so decode it first
+            if (typeof content === 'string' && /^[A-Za-z0-9+/=]+$/.test(content)) {
+              console.log('📄 Content appears to be base64-encoded, decoding first...');
+              try {
+                const decodedJsonString = atob(content);
+                console.log('📄 Decoded JSON string:', {
+                  length: decodedJsonString.length,
+                  startsWith: decodedJsonString.substring(0, 20),
+                  isJson: decodedJsonString.startsWith('{')
+                });
+                
+                // Parse the decoded JSON string
+                const nestedJson = JSON.parse(decodedJsonString);
+                console.log('📄 Parsed nested JSON:', {
+                  hasContent: 'content' in nestedJson,
+                  hasDocumentCount: 'documentCount' in nestedJson,
+                  keys: Object.keys(nestedJson)
+                });
+                
+                if (nestedJson && typeof nestedJson === 'object' && 'content' in nestedJson) {
+                  const innerContent = nestedJson.content;
+                  const isBase64 = /^[A-Za-z0-9+/=]+$/.test(innerContent);
+                  
+                  console.log('📄 Extracted inner content:', {
+                    innerContentLength: innerContent?.length,
+                    innerContentPreview: innerContent?.substring(0, 100) + '...',
+                    isBase64: isBase64
+                  });
+                  
+                  if (isBase64) {
+                    // It's base64-encoded PDF content
+                    content = innerContent;
+                  } else {
+                    // It's plain text content, not a PDF
+                    console.log('📄 Inner content is plain text, not PDF. This appears to be a text file with PDF extension.');
+                    // Return the text content for the FilePreview to handle as text
+                    return { 
+                      success: true, 
+                      previewUrl: null, 
+                      blob: null, 
+                      isJsonContent: true, 
+                      decodedContent: innerContent,
+                      isTextContent: true
+                    };
+                  }
+                }
+              } catch (decodeError) {
+                console.warn('⚠️ Failed to decode base64 content or parse JSON:', decodeError);
+              }
+            }
+            
+            console.log('📄 Processing base64 PDF content:', {
+              contentLength: content?.length,
+              mimeType: responseMimeType,
+              contentPreview: content?.substring(0, 100) + '...',
+              firstChars: content?.substring(0, 20),
+              lastChars: content?.substring(content.length - 20),
+              isBase64: /^[A-Za-z0-9+/=]+$/.test(content)
+            });
+            
+            // Decode base64 content
+            let decodedContent;
+            try {
+              decodedContent = atob(content);
+              console.log('📄 Base64 decode successful:', {
+                originalLength: content.length,
+                decodedLength: decodedContent.length,
+                firstBytes: decodedContent.substring(0, 10),
+                firstBytesHex: Array.from(decodedContent.substring(0, 10)).map(c => c.charCodeAt(0).toString(16).padStart(2, '0')).join(' ')
+              });
+              
+              // Verify it's actually a PDF
+              const isPDF = decodedContent.startsWith('%PDF');
+              console.log('📄 PDF header verification:', {
+                isPDF: isPDF,
+                firstBytes: decodedContent.substring(0, 4),
+                firstBytesHex: Array.from(decodedContent.substring(0, 4)).map(c => c.charCodeAt(0).toString(16).padStart(2, '0')).join(' '),
+                first20Chars: decodedContent.substring(0, 20)
+              });
+              
+              if (!isPDF) {
+                console.warn('⚠️ Decoded content does not appear to be a valid PDF');
+                console.log('📄 Full decoded content preview:', decodedContent.substring(0, 200));
+              }
+              
+            } catch (decodeError) {
+              console.error('❌ Failed to decode base64 PDF content:', decodeError);
+              throw new Error('Failed to decode PDF content');
+            }
+            
+            // Create a blob from the decoded PDF content
+            // Convert string to Uint8Array for proper binary handling
+            const uint8Array = new Uint8Array(decodedContent.length);
+            for (let i = 0; i < decodedContent.length; i++) {
+              uint8Array[i] = decodedContent.charCodeAt(i);
+            }
+            
+            const blob = new Blob([uint8Array], { type: 'application/pdf' });
+            const url = window.URL.createObjectURL(blob);
+            
+            console.log('🔗 Created PDF blob URL from base64:', url, {
+              blobSize: blob.size,
+              blobType: blob.type,
+              url: url,
+              uint8ArrayLength: uint8Array.length,
+              firstBytes: Array.from(uint8Array.slice(0, 4)).map(b => String.fromCharCode(b)).join(''),
+              firstBytesHex: Array.from(uint8Array.slice(0, 4)).map(b => b.toString(16).padStart(2, '0')).join(' ')
+            });
+            
+            return { success: true, previewUrl: url, blob: blob, isJsonContent: true, decodedContent: decodedContent };
+          } else {
+            throw new Error('No content field in PDF response');
+          }
+        } catch (jsonError) {
+          console.log('📄 JSON PDF response failed, trying blob response...', jsonError);
+          
+          // Fallback to blob response
+          const previewData = await request({
+            url: `/api/files/${fileId}/preview`,
+            method: 'get',
+            additionalConfig: { 
+              responseType: 'blob',
+              validateStatus: function (status: number) {
+                return status >= 200 && status < 300;
+              }
+            }
+          });
+          
+          console.log(`✅ PDF blob preview successful for: ${fileName}`, { 
+            size: previewData.size, 
+            type: previewData.type,
+            expectedType: 'application/pdf'
+          });
+          
+          const url = window.URL.createObjectURL(previewData);
+          
+          return { success: true, previewUrl: url, blob: previewData, isJsonContent: false };
+        }
+      }
+      
+      // For other files, first try to get JSON response (for text-based files)
       try {
         const jsonResponse = await request({
           url: `/api/files/${fileId}/preview`,
diff --git a/src/locales/de.ts b/src/locales/de.ts
index 564ea55..7f961f5 100644
--- a/src/locales/de.ts
+++ b/src/locales/de.ts
@@ -375,6 +375,8 @@ export default {
     'files.preview.loading': 'Vorschau wird geladen...',
     'files.preview.unsupported': 'Vorschau für diesen Dateityp nicht verfügbar',
     'files.preview.error': 'Fehler beim Laden der Vorschau',
+    'files.preview.textInPdfFile': 'Textvorschau',
+    'files.preview.pdfFileCorrupted': 'Diese Datei scheint beschädigt zu sein. Sie hat eine PDF-Erweiterung, enthält aber Textinhalte. Bitte laden Sie die Datei erneut hoch, falls möglich.',
 
     // Workflows Page
     'workflows.title': 'Workflows',
diff --git a/src/locales/en.ts b/src/locales/en.ts
index e09d5dd..c84d51f 100644
--- a/src/locales/en.ts
+++ b/src/locales/en.ts
@@ -378,6 +378,8 @@ export default {
     'files.preview.loading': 'Loading preview...',
     'files.preview.unsupported': 'Preview not available for this file type',
     'files.preview.error': 'Error loading preview',
+    'files.preview.textInPdfFile': 'Text Preview',
+    'files.preview.pdfFileCorrupted': 'This file appears to be corrupted. It has a PDF extension but contains text content. Please re-upload the file if possible.',
 
     // Workflows Page
     'workflows.title': 'Workflows',
diff --git a/src/locales/fr.ts b/src/locales/fr.ts
index fdcbf8c..d5d665c 100644
--- a/src/locales/fr.ts
+++ b/src/locales/fr.ts
@@ -378,6 +378,8 @@ export default {
     'files.preview.loading': 'Chargement de l\'aperçu...',
     'files.preview.unsupported': 'Aperçu non disponible pour ce type de fichier',
     'files.preview.error': 'Erreur lors du chargement de l\'aperçu',
+    'files.preview.textInPdfFile': 'Aperçu du texte',
+    'files.preview.pdfFileCorrupted': 'Ce fichier semble être corrompu. Il a une extension PDF mais contient du contenu texte. Veuillez le télécharger à nouveau si possible.',
 
     // Workflows Page
     'workflows.title': 'Workflows',