Teams connection issues (error AADSTS50020)

Hello,

it seems that some attendees have issues with logging to the Teams meeting and they receive following error message:

AADSTS50020: User account '<user_email>' from identity provider 'live.com' does not exist in tenant '<STMicroelectronics or other organization>' and cannot access the application '5e3ce6c0-2b1f-4285-8d4b-75ee78787346'(Microsoft Teams Web Client) 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.

The problem seems to be somehow related to the login process and perhaps some previous invitations.

The solution could be to:

1. Go to microsoft.com, logout and login again, then follow the link
2. Open the link in the incognito mode of the browser (this should be quite reliable)

UPDATE: Note that if you don't have Microsoft/Teams account, you should be able to join without registration as a guest.

Please let us know if you faced this issue, and if the proposed workaround worked.

Best regards,

Adam Berlinger