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Reactivated M365 User is shown as "Unknown User" in Teams

Anonymous
2023-10-04T12:47:20+00:00

...and can't be added to other Teams.

I can find her user when adding new users to a team, but when adding her, "An error occured".

Her user is shown as "Unknown User" in the 1:1 Chats.

The M365 user has been reactivated, was dormant for 3 years, and it shows everywhere as active.

Is there anything I can do?

Microsoft Teams | Microsoft Teams for business | Other

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  1. Anonymous
    2023-10-04T14:42:56+00:00

    Hello Philipp R,

    I'm Ibhadighi and I'd happily help you with your question. In this forum, we are Microsoft consumers just like yourself.

    I’m sorry to hear that you’re having trouble with a reactivated user in Microsoft Teams. This issue can sometimes occur due to synchronization delays between Azure Active Directory (AAD) and Teams. Here are a few steps you can take to try and resolve this issue:

    1. Check the user’s license in Active Directory: Make sure the user has been assigned a Teams license in Active Directory. You can do this by clicking on Users, selecting the user, and clicking on Licenses > Office 365 E3 > Microsoft Teams. If it’s Off, please turn it on then click Save, and check in the Teams admin again.
    2. Clear Teams cache: Sign out and then quit the Teams desktop client. Navigate to C:Users<UserName>AppDataRoamingMicrosoftTeams (Note: The AppData folder may be hidden, in this case, please go to View on the ribbon, then tick the “Show Hidden folders” box.) Delete all the content from this folder. Restart Microsoft Teams.
    3. Change AAD settings: This issue can occur when the value UsersPermissionToReadOtherUsersEnabled is set to False in AAD5. To correct the issue, change this setting to True.
    4. Change Coexistence mode: Change the Coexistence mode for your organization from ‘Islands’ to ‘Teams only’.
    5. Wait for synchronization: Sometimes, new or reactivated users may appear as “Unknown User” in Microsoft Teams Chats for a few days after their account is activated in Azure AD1. The issue usually resolves itself after a few days.

    https://answers.microsoft.com/en-us/msteams/forum/all/new-users-sometimes-appear-as-unknown-user-in/d1bc304e-3e44-460b-a9bb-40ecc8859bf1

    I hope this helps.

    Best regards, Ibhadighi

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  2. Anonymous
    2024-01-10T18:54:46+00:00

    I want to applaud the IA for offering a real solution to the issue, rather than a blanket "Hello I am a MS IA and I will help you..." nonsense. Its really cool to see real help being offered.

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  3. Anonymous
    2023-10-05T14:25:00+00:00

    Hello Philipp R,

    Thank you so much for letting me know, glad to have been of help.

    Best regards, Ibhadighi

    “Give back to the Community. Help the next person who has this issue by indicating if this reply solved your problem. Click Yes or No below. “

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  4. Anonymous
    2023-10-05T08:58:16+00:00

    Hello Ibhadighi,

    thank you very much for your prompt reply.

    You were right - it seems that everything was configured correctly, and your 5th bullet point resolved it: After a day everything is now displayed as it should.

    Thank you very much.

    Philipp

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