Update app.py

app.py

@@ -121,7 +121,7 @@ def build_full_html(markdown_text, styles, include_fontawesome):
     
     return full_html
 
-# --- API ENDPOINT for Conversion (REVERTED) ---
+# --- API ENDPOINT for Conversion (CHANGED) ---
 @app.route('/convert', methods=['POST'])
 def convert_endpoint():
     data = request.json
@@ -133,10 +133,11 @@ def convert_endpoint():
             include_fontawesome=data.get('include_fontawesome', False)
         )
         
-        # The 'xvfb' option has been removed as requested.
+        # This combines the fixes: using xvfb to prevent the ProtocolUnknownError.
         options = {
             "quiet": "", 
             'encoding': "UTF-8",
+            'xvfb': ''
         }
 
         temp_html_path = os.path.join(TEMP_DIR, f"{uuid.uuid4()}.html")