microsoft/semantic-kernel · error · AgentInvokeException

No response from DirectLine Bot.

Error message

No response from DirectLine Bot.

What it means

An AgentInvokeException raised in get_response() when invoke() yields zero response messages. The method collects all streamed responses; if none arrive it cannot return a ChatMessageContent and aborts. This typically means the bot produced no message activities meeting the filter criteria (non-user 'message'/'bot' role activities).

Solutions

1. Inspect the raw activities collected during invoke (enable debug logging) to see what roles/types arrived.
2. Verify the conversation is live and the posted activity was accepted (check the post-activity response).
3. Confirm the bot is configured to reply with message-type activities from a non-user role.

Example fix

// before
responses = []
async for response in self.invoke(history, arguments, **kwargs):
    responses.append(response)
if not responses:
    raise AgentInvokeException("No response from DirectLine Bot.")

// after  # log raw activities for diagnosis first
responses = []
async for response in self.invoke(history, arguments, **kwargs):
    responses.append(response)
if not responses:
    logger.debug("Raw response_data was: %s", last_response_data)
    raise AgentInvokeException("No response from DirectLine Bot.")

try:
    resp = await agent.get_response(history)
except AgentInvokeException as e:
    if "No response" in str(e):
        logger.warning("Bot produced no message activities; check filters/role mapping.")
    raise

When it happens

Trigger: self.invoke(history) completes its async iteration producing an empty list — the bot returned only non-message activities, only user-originated activities, or ended without any reply.

Common situations: The DirectLine bot didn't process the activity (conversation desync); the DynamicPlanFinished event fired but no assistant message preceded it; role filtering dropped all activities because 'from.role' was unexpected.

Related errors

• Invalid response from DirectLine Bot.\n
• Conversation ID not found in start response.
• Exception occurred while fetching token.
• Failed to fetch token from token endpoint.
• Failed to generate token using bot_secret.

AI-assisted analysis of microsoft/semantic-kernel@c028a0c7dc (2026-08-13). Data as JSON: /api/errors/7cb1677932e27d04. Report an issue: GitHub.

Appendix: source

Thrown at python/samples/demos/copilot_studio_agent/src/direct_line_agent.py:99

            raise AgentInvokeException("Exception occurred while fetching token.") from ex

    @trace_agent_get_response
    @override
    async def get_response(
        self,
        history: ChatHistory,
        arguments: dict[str, Any] | None = None,
        **kwargs: Any,
    ) -> ChatMessageContent:
        """
        Get a response from the DirectLine Bot.
        """
        responses = []
        async for response in self.invoke(history, arguments, **kwargs):
            responses.append(response)

        if not responses:
            raise AgentInvokeException("No response from DirectLine Bot.")

        return responses[0]

    @trace_agent_invocation
    @override
    async def invoke(
        self,
        history: ChatHistory,
        arguments: dict[str, Any] | None = None,
        **kwargs: Any,
    ) -> AsyncIterable[ChatMessageContent]:
        """
        Send the latest message from the chat history to the DirectLine Bot
        and yield responses. This sends the payload after ensuring that:
          1. The token is fetched.
          2. A conversation is started.
          3. The activity payload is posted.
          4. Activities are polled until an event "DynamicPlanFinished" is received.

View on GitHub (pinned to c028a0c7dc)