Update app.py

app.py

@@ -48,7 +48,7 @@ def construct_index(directory_path):
     index = GPTSimpleVectorIndex(
         documents, llm_predictor=llm_predictor, prompt_helper=prompt_helper
     )
-
+    index.registry.add_type_to_struct(1, {"answer": str, "question": str})
     index.save_to_disk('index.json')
 
     return index