Subject: Request — Guest user addition / AADSTS50020 sign-in failure (PII removed)

Question

Subject: Request — Guest user addition / AADSTS50020 sign-in failure (PII removed)

KONSTANTINOS PALIERAKIS 0

Hello,

I am the administrator for the PII removed tenant. A user/account from my tenant (PII removed) is receiving the following error when trying to access Microsoft Teams in the PII removed tenant:

Error: AADSTS50020 — "User account 'PII removed' from identity provider 'https://sts.windows.net/PIIremoved/' does not exist in tenant 'PIIremoved' and cannot access the application 'PIIremoved' (Microsoft Teams). The account needs to be added as an external user in the tenant first."

Affected user: PIIremoved(belongs to tenant PIIremoved)

Please perform the following checks/actions:

In PIIremoved tenant, search Azure AD → Users for PIIremoved. If missing, add as Guest user (Azure AD → Users → New guest user → Invite user).
Check Azure AD sign-in logs for the above Request Id / Correlation Id / Timestamp to see why authentication failed and which application / conditional access policy blocked access.
Review External Identities / Cross-tenant access settings for any restrictions that could block B2B invites or access.
Advise if you prefer to invite the user differently (e.g., direct Teams meeting invite) or if additional tenant settings must be changed.

If you need tenant IDs, screenshots, or me to initiate the invite, please tell me the preferred next step.

Thanks,

Sridevi Machavarapu 22,705 Reputation points Microsoft External Staff Moderator

2026-02-17T01:50:11.8066667+00:00

Hello KONSTANTINOS PALIERAKIS,

Let's continue this discussion in Private messages tab.
Sridevi Machavarapu 22,705 Reputation points Microsoft External Staff Moderator

2026-02-19T10:35:11.27+00:00

Hello KONSTANTINOS PALIERAKIS,

Could you confirm whether your issue is resolved or still facing any errors? Please share the required details in private message to proceed further.
KONSTANTINOS PALIERAKIS 0 Reputation points

2026-02-19T12:47:00.3533333+00:00

We followed your instructions but were unable to resolve the issue. We still cannot sign in to Teams. Please help us — we urgently need Teams because it is essential for our work.
Sridevi Machavarapu 22,705 Reputation points Microsoft External Staff Moderator

2026-02-19T12:49:56.7+00:00

Hello KONSTANTINOS PALIERAKIS,

Please confirm whether the issue is with signing into Azure Portal or with Microsoft Teams?
KONSTANTINOS PALIERAKIS 0 Reputation points

2026-02-19T12:56:23.1566667+00:00

We believe the problem is that we accidentally created the same user twice: a personal account and a work account . The personal account is blocked and we cannot delete it. Could you please delete the personal account and keep only the work account ? The user is the same for both accounts: Please help us — we would be very grateful.
KONSTANTINOS PALIERAKIS 0 Reputation points

2026-02-19T12:58:01.27+00:00

the problem concerns signing into the teams
KONSTANTINOS PALIERAKIS 0 Reputation points

2026-02-19T13:11:37.1333333+00:00

I confirm to you that the problem is that we cannot signing into the microsoft teams
KONSTANTINOS PALIERAKIS 0 Reputation points

2026-02-19T14:21:32.9666667+00:00

Do you have any updates on the progress of the problem?
KONSTANTINOS PALIERAKIS 0 Reputation points

2026-02-20T07:50:10.2933333+00:00

Good morning,

I would like to inquire if there are any updates concerning the connectivity issue with Microsoft Teams.

As Teams is a critical tool for our organization, we would greatly appreciate your prompt assistance in resolving this matter.

Thank you very much for your support.
Sridevi Machavarapu 22,705 Reputation points Microsoft External Staff Moderator

2026-02-20T10:10:04.4+00:00

Hello KONSTANTINOS PALIERAKIS,

As the issue is with Microsoft Teams, I changed your question's channel tag to Microsoft Teams related. Hope someone from that team who is aware of this issue can look into this.