Update src/txagent/txagent.py

src/txagent/txagent.py

@@ -325,8 +325,10 @@ class TxAgent:
                                 conversation=None,
                                 sub_agent_task=sub_agent_task)
 
-                            call_result = call_result.split(
-                                '[FinalAnswer]')[-1]
+                            if call_result is not None:
+                                call_result = call_result.split('[FinalAnswer]')[-1]
+                            else:
+                                call_result = "⚠️ No content returned from sub-agent."
                         else:
                             call_result = "Error: The CallAgent has been disabled. Please proceed with your reasoning process to solve this question."
                     else:
@@ -365,6 +367,7 @@ class TxAgent:
         else:
             return revised_messages, existing_tools_prompt, special_tool_call
 
+
     def get_answer_based_on_unfinished_reasoning(self, conversation, temperature, max_new_tokens, max_token, outputs=None):
         if conversation[-1]['role'] == 'assisant':
             conversation.append(