Can't install app in private channel

[jerbob92]

Describe the bug
I have updated my app to manifest version 1.25, and added the "supportsChannelFeatures": "tier1".
I have also removed the supportedChannelTypes to get through the validation.

When trying to add the app to a private channel, it does allow it, but nothing seems to happen, it just opens the channel with a new message that tags the bot. The bot never gets anything to indicate it was installed, and it also doesn't receive any messages.

To Reproduce

1. Create an app on manifest 1.25 that allows installing in private channels
2. Install the app to the tenant
3. Install the app in the team
4. Try to add the app to the private channel
5. See that nothing happens.

Expected behavior
The bot should get a message that it was added to a channel and should receive messages from the channel.

Screenshots

VS Code Extension Information (please complete the following information):

CLI Information (please complete the following information):

Additional context

[m365-agent-toolkit-assistant]

👋 Hi @jerbob92,

Thank you for reporting this issue! We want to let you know that:

⏱️ Our team will personally review your issue
🎯 You can expect a response within 2 business days

✨ This is an AI-generated initial response
🤖 AI-Generated Preliminary Analysis:

This issue is a known limitation during the rollout of manifest v1.25 and "supportsChannelFeatures": "tier1" for private channels. Currently:

• Toolkit and server-side validation block publishing with manifest v1.25.
• Even after updating the manifest, bots do not reliably receive "installed" events or channel messages in private channels.

Workaround:
No effective workaround exists until Microsoft completes the upstream API and toolkit updates required for private channel support with manifest v1.25. For now, bots may not function as expected in private channels, and app installation is inconsistent.

Recommended Action:

• Monitor this GitHub issue for fixes and updates.
• Ensure you are using the latest Microsoft 365 Agents Toolkit and Teams client version.
• If critical, revert to public channels for bot interactions or consider removing "supportsChannelFeatures" temporarily.

Apologies for the inconvenience—this is an active platform bug, not a code issue.

✨We'd love your feedback! Please take a moment to fill out our survey.

---

Note: This is an automated first response generated by AI. A human team member will review your issue and provide a more detailed response soon. We appreciate your patience!

[jerbob92]

I have found out that Microsoft has paused rollout of apps in private channels:

It's a it odd because the documentation makes it looks like it's fully supported already: https://learn.microsoft.com/en-us/microsoftteams/platform/build-apps-for-shared-private-channels?tabs=tabs%2Cexternal-users%2Csharedchannel

[tecton]

Hi @jerbob92, the private channel is probably not rolled out yet. Shared channel is generally available but private channel is public developer preview.

[jerbob92]

@tecton Actually also doesn't work in developer preview. But it's probably caused by pausing the rollout of private channel support:

Updated March 17, 2026: We have paused rollout of this feature at this time and will provide updates via this post when we are ready to proceed. We apologize for any inconvenience.