correct hmi blcok

app.py

@@ -773,8 +773,9 @@ def chathmi4(message, history2):
             print("No need to add file in chatbot")        
 
     except Exception as e:
-        print("chathmi3 error:", e)  
-     
+        print("chathmi3 error:", e)
+      
+    return ["", history2, None, None]
     # history = history + [(message, None)]
     
     print("History2: ", history2)