Unable to log onto MS Teams

pierre coetzer 0 Reputation points

Hello, I am unable to log onto my MS Teams account for some reason. Here is the error message I'm getting:

"Selected user account does not exist in tenant 'Microsoft Services' and cannot access the application '1fec8e78-bce4-4aaf-ab1b-5451cc387264' in that tenant. The account needs to be added as an external user in the tenant first. Please use a different account".

It all seemed to work until last month - no suddenly no more. What could be the reason ?

Microsoft Teams
Microsoft Teams
A Microsoft customizable chat-based workspace.
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  1. SokiGuo-MSFT 24,936 Reputation points Microsoft Vendor

    Hi @pierre coetzer

    There are many reasons why you can't sign in. First of all, you need to isolate whether the issue is a desktop application, log in to the Teams web client in privacy mode to see if the problem persists.

    If you're still having issues with Teams web client, you can try contacting your admin to run the following tests to troubleshoot.

    1. Select the following button to populate the diagnostic in the Microsoft 365 admin center: Run Tests: Teams Sign-in
    2. In the User Name or Email Address field, enter the email address of the user who's experiencing the Teams sign-in issue.

    For more details about Teams sign-in errors, you could refer to:


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