Copilot Studio agent published to Teams: “Bad request” when adding after updates and republishing

Question

I have a Copilot Studio agent that I built and published to both Microsoft Teams and Microsoft 365 Chat. The agent was working correctly in both locations until I made general updates to the agent and republished it.

The updates did not involve permission changes, security changes, channel access changes, user access changes, or Teams app policy changes.

After republishing, the agent still works in Microsoft 365 Chat, but it no longer works in Teams.

Service / technologies involved

Copilot Studio

Microsoft Teams

Microsoft 365 Chat

Expected result

After making general updates and republishing the Copilot Studio agent, I expect the agent to remain available in Teams and be addable from the Teams app listing.

Actual result

In Teams, the agent appears under Built with Power Platform. When I click the agent, the details page opens and appears to show the correct published version. However, when I click Add, Teams returns the following error:

Bad request

Steps to reproduce

Create a Copilot Studio agent.

Publish the agent to Teams and Microsoft 365.

Confirm that the agent works in Teams and Microsoft 365 Chat.

Make general updates to the agent that do not involve permissions, security, access, or Teams app policy changes.

Republish the agent.

Open Teams.

Go to the agent under Built with Power Platform.

Click the agent to open the details page.

Click Add.

Teams returns “Bad request.”

Troubleshooting already attempted

I have already tried the following:

Tested in the Teams desktop app

Tested in Teams on the web

Cleared the Teams cache

Signed out and signed back in

Removed the Teams and Microsoft 365 channels from the agent

Re-added the channels

Republished the agent again

The issue still occurs.

Additional context

This has happened before with other Copilot Studio agents after making general updates and republishing. The issue appears to affect Teams only, because the same agent continues to work in Microsoft 365 Chat.

Question

How can I resolve the “Bad request” error in Teams after updating and republishing a Copilot Studio agent? Is there a known issue or additional cleanup step required when an already-published agent is updated and republished for Teams?

Answer

Resolved — posting the root cause and fix in case anyone else hits this, because the actual error is buried and the "Bad request" message in Teams is misleading.

Root cause: The agent's display name exceeded 30 characters. The Teams app manifest schema requires name.short to be ≤ 30 characters. Copilot Studio takes the agent's display name and writes it into name.short when it generates the Teams app definition on publish. If the name is over 30 characters, the generated manifest fails schema validation at the Teams settings store, and every Add attempt fails with a generic "Bad request."

In my case I renamed the agent from a 29 character name to a 38 character name which is over the limit. That single rename was the breaking change. The first publish before the rename worked because the name fit; every republish after the rename silently produced a manifest that Teams rejected.

How to confirm it's the same issue: Open Teams on the web, F12 → Network tab, click Add. Find the failing POST to /api/mt/part/{region}/beta/users/apps/templatedInstance/entitlements (status 400). Look at the Response body. If it contains something like:


"Failed to execute settings store request: .../apps/{appId}/definitionv2, StatusCode: 400, ReasonPhrase: Schema validation errors"

...then the manifest is failing schema validation, and the name length is the most likely cause (check icon dimensions and description length as secondary suspects).

Product feedback for Microsoft if anyone from the team sees this: Copilot Studio should either enforce the 30-char limit at rename time, truncate the name when generating name.short, or surface the schema validation error in the publish UI. Silently writing an invalid manifest and surfacing the failure as a generic "Bad request" only on the end user's Add click is a rough debugging experience — especially because the agent appears to publish successfully and works in M365 Chat, so there's no obvious signal that anything is wrong until users try to install.

Answer

Hello SamJakub,
This is a known issue. The "Add → Bad request" error in Teams after a republish usually means Copilot Studio has republished the agent payload, but the Teams app package (manifest + app id) cached in the Teams Admin Center / Teams app catalog is now out of sync with it. M365 Chat doesn't rely on that app-catalog entry, so it keeps working.

Fix (in order)

Teams Admin Center → Teams apps → Manage apps — look up your agent by name. Open it and choose Update / Re-publish if prompted. If it shows an old version or "needs review", approve it.
In Copilot Studio → Channels → Microsoft Teams and Microsoft 365 Copilot → Availability options → Show in Teams and Microsoft 365 Copilot → Edit details / Download manifest. Download the .zip and have a tenant admin upload it to Teams Admin Center → Manage apps → Upload new app (or Upload an update if an entry already exists). This re-syncs the manifest, app id, and icons.
Remove the old org-catalog entry for the agent in Teams Admin Center, wait a few minutes, then re-publish from Copilot Studio. The "Built with Power Platform" listing is a cached pointer — it can survive a deleted/replaced backend and produce exactly the "Bad request" you see on Add.
If you changed the agent name or icon during the update, Teams treats the upload as a new app — the cached tile points to the previous app id. Delete the old tile.
Tenant cache: after admin-center changes, allow up to ~24 h for the Teams client app catalog to refresh; force a refresh by Apps → Manage your apps → Refresh, or have one user reinstall to validate.

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