Unknown user (invalid.teams.ms)

This is the recent message received from Microsoft:
"we have identified the issue that caused the new users to be shown as "Unknown Users". The mitigation is released, so new users can proceed normally. We are now working on recovering the Unknown User group. "

I found a workaround if you really need to communicate with someone in the meantime -- from the Unknown User's account:

1. Add people you know by their email address (this sends them a request that they cannot accept)
2. Under the added person: ... (3 dots) Schedule Meeting > SEND
3. The added person should be able to accept the meeting invite and you can communicate in the meeting invite area for now.

Microsoft has now official posted this service issue. You can use this website to monitor updates

https://status.cloud.microsoft/

Another temporary fix to this problem is to make a group chat with lets say, an alt account and add the unknown user account to the group chat. You should now be able to talk to them until this issue is fixed.

Hello Ratish Acharya,

Thank you for reaching out, and I appreciate the detailed description of the issue — your troubleshooting steps have been very thorough.

The "Unknown User (invalid.teams.ms)" and "Something went wrong" errors you're experiencing typically related to how Teams provisions and caches user identities on the backend.

To narrow this down properly, can you confirm when did you and your friend create these Teams personal accounts?

If the accounts were created recently, your accounts may still be in a provisioning state. The Teams service-side cache and identity resolution system can take 24 to 72 hours (and in some cases up to 7 days) to fully propagate and resolve new user profiles. I would recommend:

1. Wait 24–72 hours from the time of account creation for the provisioning to fully complete.
2. After the waiting period, sign out completely from Teams on the browser, clear your browser cache and cookies, and then sign back in.
3. Have your friend do the same on their end.

If the accounts are not new or the issue persists after 72 hours, since you've already gone above and beyond with your troubleshooting (clearing cache, using incognito mode, deleting and recreating the account, and testing across browsers), there's very little left to try from the client side. At this point, the issue likely requires a backend investigation by Microsoft support.

I recommend reaching out to Teams live support directly so they can look into the identity provisioning and profile mapping on the server side for your accounts:

• Go to OneCustomer | Chat Support, fill in your details and describe your issue, and select submit

A support agent will be able to verify whether your Teams chat identity provisioning is fully completed or stuck and take corrective action from the backend if needed.

I hope this helps clarify what might have transpired — please let me know when the accounts were created and how it goes after the waiting period. I'm happy to assist further!

Best regards

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