fix errors with gemini message format in chats

autogen/agentchat/chat.py

@@ -107,6 +107,15 @@ def __find_async_chat_order(chat_ids: Set[int], prerequisites: List[Prerequisite
     return chat_order
 
 
+def _post_process_carryover_item(carryover_item):
+    if isinstance(carryover_item, str):
+        return carryover_item
+    elif isinstance(carryover_item, dict) and "content" in carryover_item:
+        return str(carryover_item["content"])
+    else:
+        return str(carryover_item)
+
+
 def __post_carryover_processing(chat_info: Dict[str, Any]) -> None:
     iostream = IOStream.get_default()
 
@@ -116,7 +125,7 @@ def __post_carryover_processing(chat_info: Dict[str, Any]) -> None:
             UserWarning,
         )
     print_carryover = (
-        ("\n").join([t for t in chat_info["carryover"]])
+        ("\n").join([_post_process_carryover_item(t) for t in chat_info["carryover"]])
         if isinstance(chat_info["carryover"], list)
         else chat_info["carryover"]
     )

autogen/agentchat/conversable_agent.py

@@ -11,6 +11,7 @@
 
 from openai import BadRequestError
 
+from autogen.agentchat.chat import _post_process_carryover_item
 from autogen.exception_utils import InvalidCarryOverType, SenderRequired
 
 from .._pydantic import model_dump
@@ -2364,7 +2365,7 @@ def _process_carryover(self, content: str, kwargs: dict) -> str:
         if isinstance(kwargs["carryover"], str):
             content += "\nContext: \n" + kwargs["carryover"]
         elif isinstance(kwargs["carryover"], list):
-            content += "\nContext: \n" + ("\n").join([t for t in kwargs["carryover"]])
+            content += "\nContext: \n" + ("\n").join([_post_process_carryover_item(t) for t in kwargs["carryover"]])
         else:
             raise InvalidCarryOverType(
                 "Carryover should be a string or a list of strings. Not adding carryover to the message."