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alexander_999's avatar
alexander_999
Copper Contributor
Sep 30, 2026

Unable to access Teams from a PC (only mobile access)

We have a user who can't access Teams on PC, but it works as usual on mobile (however, no connections to Outlook for Teams or the ability to create Teams meetings). Have tested several different PC’s as well as app and browser, none of them work.

The problem is that the user cannot find the primary organization when logging in to Teams and it only shows guest organizations (which cannot be connected to either).

Below is the answer I got when I made a diagnosis of the login problems. I have found that this "guest account" is Microsoft.com, but that does not remove the fact that the primary organization does not show up at all. Do not know if anyone has seen this before or knows what to do. So all kinds of info are helpful because I am completely out of ideas.

 

 

What identifies the right external organization

  1. User: Name (email address removed for privacy reasons)
  2. App: Microsoft Teams
  3. Type of access: B2B collaboration
  4. Error code: 500571
  5. Error: Guest account is disabled
  6. External target tenant: f8cdef31-a31e-4b4a-93e4-5f571e91255a
  7. Correlation-ID: d7c0c004-ed20-4cd5-a056-7ce0d7f0ae24

This means that it is the organization that owns the tenant ID f8cdef31-a31e-4b4a-93e4-5f571e91255a that should be contacted. If you have several guest organizations associated with you, there is no need to guess in this case — the failed event points out exactly which external tenant received the request.

Practical way to find which organization it is

  1. Search your documentation or previous invitations by tenant ID f8cdef31-a31e-4b4a-93e4-5f571e91255a.
  2. Ask User to check which organization he was trying to switch to in Teams just when the error occurred.
  3. If you have multiple external partners with similar names, match the tenant ID to the partner you have B2B collaboration with.
  4. Please send the correlation ID and time 2026-09-09 10:43 UTC to the external administrator so that they can find the same event at their place.

Conclusion

You need to contact the external organization that corresponds to the tenant ID f8cdef31-a31e-4b4a-93e4-5f571e91255a and ask them to check Users guest account. This is where the account appears to be disabled.

Administrator
microsoft teams

1 Reply

  • Jamony's avatar
    Jamony
    MCT
    Oct 07, 2026

    Desktop and web show only guest organizations while mobile works, and AADSTS500571 identifies a disabled guest object in an external tenant. That explains failure to enter that guest tenant, but not why the home organization is missing, so treat them separately.

     

    In the home tenant, confirm the user is enabled, the UPN is correct, and the Teams service plan is active. Review Entra sign-in logs for a desktop attempt and verify which tenant received it. Sign out of every Teams account, remove stale work or school accounts from Windows, restart, and sign in using only the home account. Test Teams in a private browser window.

     

    The external tenant owner must re-enable or remove its disabled guest object. If the home tenant still does not appear, open Microsoft 365 support with the correlation ID, UTC timestamp, affected user, and home tenant ID.