accessing Microsoft apps on MacBook desktop

Question

Hello,

I am a student at the [Moderator note: Personally Identifiable Information removed], [Moderator note: Personally Identifiable Information removed]. I am able to access all Microsoft Apps on my browser but everytime I try to sign in on my desktop it keeps showing me this message:

AADSTS50020: User account from identity provider 'https://[Moderator note: Personally Identifiable Information removed]/' does not exist in tenant [Moderator note: Personally Identifiable Information removed] and cannot access the application '1fec8e78-bce4-4aaf-ab1b-5451cc387264'(Microsoft Teams) in that tenant. The account needs to be added as an external user in the tenant first. Sign out and sign in again with a different Azure Active Directory user account.

can someone please explain what's the issue?

Answer 1

Hi @Safaa Bashir, 

Good day, and thank you for reaching out. I appreciate you sharing the details of your situation.

Before we proceed, please note that this is a user-to-user community forum. As a moderator, I don’t have access to your Microsoft 365 tenant, your account, or your device to make changes directly. However, I’ll do my best to support you by sharing the appropriate resources and directing you to the right support channels. 

Based on the error message you provided, Teams on your computer appears to be trying to sign in with a Microsoft identity that is not being recognized by the university’s Microsoft environment.

This is why you are able to access Microsoft apps successfully in your browser, while the desktop app continues to return the AADSTS50020 error. The browser session is likely using the correct organizational account, while the desktop app may still be using an older sign-in session, a different Microsoft account, or a cached work/school account. 

Here are some steps you can try: 

1/ Sign out of any previously used Microsoft accounts on your desktop apps  

If you have previously signed in to Microsoft desktop apps (such as Teams, Word, or Excel) with an older, personal, or different work/school account, please sign out of all such accounts first. 

• In Microsoft Teams, if you are able to access the app interface, click your profile picture in the top-right corner and select Sign out. Then fully quit Teams so it is no longer running in the background. 
• In other Microsoft Office desktop apps such as Word or Excel, open the app, select the app name from the top menu bar, and choose Sign Out. Then quit all Office apps afterward. 

2/ Remove any existing Work/School account from your Mac 

• If your Mac still has older Microsoft account credentials saved, open Finder > Applications > Utilities > Keychain Access.  
• Locate any saved credentials related to a previously used Microsoft work or school account that you no longer use, and remove those entries if recognized. 
• After doing this, restart your Mac.  

3/ Sign back in using your university account 

• After restarting, open Microsoft Teams and sign in with your university account.
• If prompted, choose the Work or School account option and continue with your university credentials.  
• If needed, you may also verify your CCID username/password through the university’s official CCID page before trying again.  

4/ Contact your IT department 

If the issue continues after trying the steps above, I would recommend contacting your university's IT department. They can verify whether your account has been correctly set up in the organization’s Microsoft environment and whether the appropriate access has been assigned. Settings such as account provisioning, tenant membership, and access permissions are managed on the institution’s side and typically can only be reviewed or changed by the IT administrator. 

• In case you do not know who is your IT admin, kindly refer to this article: How do I find my Microsoft 365 admin? - Microsoft Support  

I hope this information is helpful. Should you have any further questions or need additional assistance, please feel free to share them in the comment below. I'm very happy to help.  

Thank you again for your understanding and cooperation. 

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