When Microsoft Teams shows you as an "external" user, it's usually because your account is no longer associated with your organization's Microsoft 365 tenant.
- Check your account status: please confirm that you are still a member of your organization. If your account was removed or permissions were changed, you may be considered an external user.
- Rejoin your organization: If you were removed, contact your organization's admin to re-invite you to Teams. Admins can do this from the Microsoft Teams admin center or the Microsoft 365 admin center.
- Teams web client: Try signing in using the Teams web client to see if you are still listed as an external user. If the web version works, the problem may be with the desktop client.
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