Fix: Remove assertions, ensure demo always exists with proper fallbacks

app.py

@@ -999,11 +999,19 @@ try:
             """)
         logger.info(f"Error demo created: {type(demo)}")
         # Don't re-raise - let the demo be created so users can see the error
-    logger.info(f"Demo created successfully: {type(demo)}")
-    # Explicitly verify it's a valid Gradio object
-    if not isinstance(demo, (gr.Blocks, gr.Interface)):
-        raise TypeError(f"Demo is not a valid Gradio object: {type(demo)}")
-    logger.info("Demo validation passed - ready for Spaces")
+    
+    # Verify demo was created
+    if demo is None:
+        logger.error("Demo is None after creation attempt!")
+        with gr.Blocks(title="CGT-LLM-Beta RAG Chatbot") as demo:
+            gr.Markdown("# Error: Demo was not created\n\nPlease check the logs.")
+    elif not isinstance(demo, (gr.Blocks, gr.Interface)):
+        logger.error(f"Demo is not a valid Gradio object: {type(demo)}")
+        with gr.Blocks(title="CGT-LLM-Beta RAG Chatbot") as demo:
+            gr.Markdown(f"# Error: Invalid demo type\n\nType: {type(demo)}\n\nPlease check the logs.")
+    else:
+        logger.info(f"Demo created successfully: {type(demo)}")
+        logger.info("Demo validation passed - ready for Spaces")
 except Exception as e:
     logger.error(f"Error creating demo: {e}", exc_info=True)
     import traceback
@@ -1030,8 +1038,16 @@ else:
 
 # CRITICAL: Ensure demo is always set for Spaces
 # Spaces will look for a variable named 'demo' at module level
-assert demo is not None, "Demo must be set for Spaces"
-assert isinstance(demo, (gr.Blocks, gr.Interface)), f"Demo must be a Gradio object, got {type(demo)}"
+# Final safety check - if demo is still None or invalid, create a minimal one
+if demo is None or not isinstance(demo, (gr.Blocks, gr.Interface)):
+    logger.error("CRITICAL: Demo is invalid, creating emergency fallback")
+    with gr.Blocks(title="CGT-LLM-Beta RAG Chatbot") as demo:
+        gr.Markdown("""
+        # CGT-LLM-Beta RAG Chatbot
+        
+        The application encountered an error during initialization.
+        Please check the logs for details.
+        """)
 
 # For local execution only (not on Spaces)
 if __name__ == "__main__":