Fix GroupChatError

✅ Solution

GroupChatError often arises from incorrect agent configurations within the GroupChat object, such as mismatched or missing LLM configurations or incompatible function definitions. Ensure each agent has a properly defined `llm_config` compatible with its intended model and that function definitions align with the agent's role; verify all agents needed for the ChatGroup are added to the GroupChat object. Also confirm that the model(s) specified in the llm_config are accessible and correctly configured in your environment.