Forum Discussion

CoralieSimonaire's avatar
CoralieSimonaire
Brass Contributor
Aug 28, 2026

Copilot Studio agent suddenly stopped working in Teams

Hello, I've run into a strange issue with a Copilot Studio agent and I'm trying to understand where to investigate next. The agent is published to the "Teams and Microsoft 365 Copilot" channel and ...
ai agents
copilot studio
microsoft 365 copilot
Surya_Narayana's avatar
Surya_Narayana
MCT
Aug 29, 2026

hi CoralieSimonaire​ The fact that the agent works in Copilot Studio and Microsoft 365 Copilot, but Teams doesn't create any session in Analytics/Observability, is the biggest clue here. It suggests the request may not be reaching the Copilot Studio runtime at all.

Since another agent in the same tenant works normally in Teams, the next area to check would be the Teams channel/app configuration for this specific agent, rather than the MCP server or the agent itself.

A few things worth checking:

  • Remove the Teams channel from the affected agent, save the changes, then add and publish the Teams channel again.
  • Create a new Teams app/package for the agent instead of simply reinstalling the existing one. This can help rule out stale Teams app or bot registration information.
  • Compare the affected agent's Teams channel configuration with the working agent, particularly the app/package and publishing settings.
  • Test the agent from a fresh Teams chat or with another user account to rule out cached conversation or app state.
  • Check whether the agent's environment, agent ID, or publishing configuration changed around the time the issue started.

At this point, the MCP server may not be the area to troubleshoot. If Teams isn't creating a session at all, it suggests the request isn't reaching the Copilot Studio runtime in the first place, so the MCP tools wouldn't have an opportunity to run.

If removing/re-adding the Teams channel and creating a fresh Teams app doesn't resolve the issue, a Microsoft support case would be the next step. Include the agent ID, environment ID, approximate failure timestamps, and the fact that Teams produces no Copilot Studio session while the other channels continue to work. Those details should give the support team a useful starting point for tracing the Teams-to-Copilot Studio handoff.

The comparison with the other working agent is particularly useful. Comparing the two configurations side by side may reveal a small Teams/channel difference that's otherwise easy to miss.