diff --git a/src/pages/api/upload/media.ts b/src/pages/api/upload/media.ts
index a182c48..a69ff6c 100644
--- a/src/pages/api/upload/media.ts
+++ b/src/pages/api/upload/media.ts
@@ -21,8 +21,13 @@ interface UploadResult {
 const UPLOAD_CONFIG = {
   maxFileSize: 50 * 1024 * 1024, // 50MB
   allowedTypes: new Set([
+    // Images
     'image/jpeg', 'image/jpg', 'image/png', 'image/gif', 'image/webp', 'image/svg+xml',
+    
+    // Videos
     'video/mp4', 'video/webm', 'video/ogg', 'video/avi', 'video/mov',
+    
+    // Documents
     'application/pdf',
     'application/msword',
     'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
@@ -30,7 +35,32 @@ const UPLOAD_CONFIG = {
     'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
     'application/vnd.ms-powerpoint',
     'application/vnd.openxmlformats-officedocument.presentationml.presentation',
-    'text/plain', 'text/csv', 'application/json'
+    
+    // Text files
+    'text/plain', 
+    'text/csv', 
+    'text/markdown',           // Added markdown
+    'text/x-markdown',         // Alternative markdown MIME type
+    'application/json',
+    'application/xml',
+    'text/xml',
+    'text/html',
+    
+    // Archives
+    'application/zip', 
+    'application/x-tar', 
+    'application/gzip',
+    'application/x-gzip',
+    'application/x-zip-compressed',
+    'application/x-rar-compressed',
+    'application/x-7z-compressed',
+    
+    // Additional useful formats
+    'application/rtf',         // Rich Text Format
+    'text/richtext',
+    'application/x-yaml',      // YAML files
+    'text/yaml',
+    'application/yaml'
   ]),
   localUploadPath: process.env.LOCAL_UPLOAD_PATH || './public/uploads',
   publicBaseUrl: process.env.PUBLIC_BASE_URL || 'http://localhost:4321'
diff --git a/src/pages/contribute/knowledgebase.astro b/src/pages/contribute/knowledgebase.astro
index 5863579..31af7d0 100644
--- a/src/pages/contribute/knowledgebase.astro
+++ b/src/pages/contribute/knowledgebase.astro
@@ -114,8 +114,13 @@ const sortedTools = data.tools.sort((a: any, b: any) => a.name.localeCompare(b.n
           <div class="form-group">
             <label class="form-label">Dokumente, Bilder, Videos (Optional)</label>
             <div class="upload-area" id="upload-area">
-              <input type="file" id="file-input" multiple accept=".pdf,.doc,.docx,.txt,.md,.zip,.png,.jpg,.jpeg,.gif,.mp4,.webm" class="hidden">
-              <div class="upload-placeholder">
+              <input 
+                type="file" 
+                id="file-input" 
+                multiple 
+                accept=".pdf,.doc,.docx,.txt,.md,.markdown,.csv,.json,.xml,.html,.rtf,.yaml,.yml,.zip,.tar,.gz,.rar,.7z,.png,.jpg,.jpeg,.gif,.webp,.svg,.mp4,.webm,.mov,.avi" 
+                class="hidden"
+              >              <div class="upload-placeholder">
                 <svg width="48" height="48" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1">
                   <path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4"/>
                   <polyline points="7 10 12 15 17 10"/>
@@ -342,37 +347,49 @@ class KnowledgebaseForm {
       console.log('[UPLOAD] Response status:', response.status);
       console.log('[UPLOAD] Response headers:', Object.fromEntries(response.headers.entries()));
 
+      // FIXED: Read the response body only once
+      let responseData: any;
+      let responseText: string;
+      
+      try {
+        // Try to read as text first (works for both JSON and plain text)
+        responseText = await response.text();
+        console.log('[UPLOAD] Raw response:', responseText.substring(0, 200));
+        
+        // Then try to parse as JSON
+        try {
+          responseData = JSON.parse(responseText);
+        } catch (parseError) {
+          // If JSON parsing fails, treat as plain text
+          responseData = { error: responseText };
+        }
+      } catch (readError) {
+        console.error('[UPLOAD] Failed to read response:', readError);
+        throw new Error('Failed to read server response');
+      }
+
       if (response.ok) {
-        const result = await response.json();
-        console.log('[UPLOAD] Success result:', result);
+        console.log('[UPLOAD] Success result:', responseData);
         
         fileItem.uploaded = true;
-        fileItem.url = result.url;
+        fileItem.url = responseData.url;
         this.renderFileList();
         
         this.showMessage('success', `Successfully uploaded ${fileItem.name}`);
       } else {
-        // Enhanced error handling - read the actual error from response
+        // Enhanced error handling with single response read
         let errorMessage = `Upload failed with status ${response.status}`;
         
-        try {
-          const errorData = await response.json();
-          console.error('[UPLOAD] Error response data:', errorData);
-          
-          if (errorData.error) {
-            errorMessage = errorData.error;
-          }
-          
-          // Log additional details if available
-          if (errorData.details) {
-            console.error('[UPLOAD] Error details:', errorData.details);
-            errorMessage += ` (Details: ${errorData.details.join(', ')})`;
-          }
-        } catch (parseError) {
-          console.error('[UPLOAD] Could not parse error response:', parseError);
-          const errorText = await response.text();
-          console.error('[UPLOAD] Raw error response:', errorText);
-          errorMessage += ` (Raw: ${errorText.substring(0, 100)})`;
+        if (responseData && responseData.error) {
+          errorMessage = responseData.error;
+        } else if (responseText) {
+          errorMessage += ` (${responseText.substring(0, 100)})`;
+        }
+        
+        // Log additional details if available
+        if (responseData && responseData.details) {
+          console.error('[UPLOAD] Error details:', responseData.details);
+          errorMessage += ` (Details: ${responseData.details.join(', ')})`;
         }
         
         throw new Error(errorMessage);