使用时报错： Exception in ASGI application

[hhaishen]

通过 DB-GPT 配置 MCP 工具，进行调用时，出现下面的错误

INFO: 127.0.0.1:48926 - "GET /sse HTTP/1.1" 200 OK
INFO: 127.0.0.1:48940 - "POST /messages/?session_id=f0cbfbf4b6c542dc846e6d19e0c67fdb HTTP/1.1" 202 Accepted
INFO: 127.0.0.1:48940 - "POST /messages/?session_id=f0cbfbf4b6c542dc846e6d19e0c67fdb HTTP/1.1" 202 Accepted
INFO: 127.0.0.1:48940 - "POST /messages/?session_id=f0cbfbf4b6c542dc846e6d19e0c67fdb HTTP/1.1" 202 Accepted
ERROR: Exception in ASGI application
Traceback (most recent call last):
File "/home/anaconda3/envs/mcp/lib/python3.11/site-packages/uvicorn/protocols/http/h11_impl.py", line 403, in run_asgi
result = await app( # type: ignore[func-returns-value]
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/anaconda3/envs/mcp/lib/python3.11/site-packages/uvicorn/middleware/proxy_headers.py", line 60, in call
return await self.app(scope, receive, send)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/anaconda3/envs/mcp/lib/python3.11/site-packages/starlette/applications.py", line 113, in call
await self.middleware_stack(scope, receive, send)
File "/home/anaconda3/envs/mcp/lib/python3.11/site-packages/starlette/middleware/errors.py", line 187, in call
raise exc
File "/home/anaconda3/envs/mcp/lib/python3.11/site-packages/starlette/middleware/errors.py", line 165, in call
await self.app(scope, receive, _send)
File "/home/anaconda3/envs/mcp/lib/python3.11/site-packages/starlette/middleware/exceptions.py", line 63, in call
await wrap_app_handling_exceptions(self.app, conn)(scope, receive, send)
File "/home/anaconda3/envs/mcp/lib/python3.11/site-packages/starlette/_exception_handler.py", line 53, in wrapped_app
raise exc
File "/home/anaconda3/envs/mcp/lib/python3.11/site-packages/starlette/_exception_handler.py", line 42, in wrapped_app
await app(scope, receive, sender)
File "/home/anaconda3/envs/mcp/lib/python3.11/site-packages/starlette/routing.py", line 716, in call
await self.middleware_stack(scope, receive, send)
File "/home/anaconda3/envs/mcp/lib/python3.11/site-packages/starlette/routing.py", line 736, in app
await route.handle(scope, receive, send)
File "/home/anaconda3/envs/mcp/lib/python3.11/site-packages/starlette/routing.py", line 290, in handle
await self.app(scope, receive, send)
File "/home/anaconda3/envs/mcp/lib/python3.11/site-packages/starlette/routing.py", line 78, in app
await wrap_app_handling_exceptions(app, request)(scope, receive, send)
File "/home/anaconda3/envs/mcp/lib/python3.11/site-packages/starlette/_exception_handler.py", line 53, in wrapped_app
raise exc
File "/home/anaconda3/envs/mcp/lib/python3.11/site-packages/starlette/_exception_handler.py", line 42, in wrapped_app
await app(scope, receive, sender)
File "/home/anaconda3/envs/mcp/lib/python3.11/site-packages/starlette/routing.py", line 76, in app
await response(scope, receive, send)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: 'NoneType' object is not callable