Guest accounts from one company unable to sign-in

PT Maliborski 246

Hi All,

For few years now every guest account in our tenant was signing in using their company email address.

Two days ago something changed and guest users from one company, when trying to sign in to our tenant, get error that "Selected account doesn't exist in tenant". Well, it does exist!

I have reset Redemption status, eventually I have fully removed and re-invited user - still the same message.

Users from other companies can still log in with no issues - just one company is affected.

I've opened case with Microsoft and was told that "Guest users should use tenant UPN in format of user_EXT_domain@mydomain.onmicrosoft.com".

I said "What the hell? Never had to do anything like that. This kind of UPN is difficult to re-type, crazy hard to remember".

I have passed this MS response over to the affected guests to try and still waiting for feedback, but can't imagine this is the solution.

Maybe someone has seen something like this?

Alfredo Revilla - Upwork Top Talent | IAM SWE SWA 27,246 Reputation points

2024-04-25T07:06:55.2233333+00:00

Hi, this is wrong:

Guest users should use tenant UPN in the format of user_EXT_domain@mydomain.onmicrosoft.com

You should be able to log in using the guest's original UPN. What's the detailed error?
PT Maliborski 246 Reputation points

2024-04-25T07:40:14.52+00:00

Hi @Alfredo Revilla - Upwork Top Talent | IAM SWE SWA

There is no specific error:

But obviously Guest exists:

Like I said, it only affect Guest from one company. I can sign in with my personal guest with no issues. When I attempt to login as other guest (using their company email address) it tries to log me in, ask for password or send MFA notification, but in case of this one company it just throws out the same window "We couldn't find an account with that username"
Alfredo Revilla - Upwork Top Talent | IAM SWE SWA 27,246 Reputation points

2024-04-25T07:48:19.0866667+00:00

Show me the affected user identities as shown in the portal.
PT Maliborski 246 Reputation points

2024-04-25T07:58:24.3933333+00:00

Sorry. What do you mean?
PT Maliborski 246 Reputation points

2024-04-25T08:00:20.74+00:00

Sorry. Don't understand what you mean "as shown in the portal"
Alfredo Revilla - Upwork Top Talent | IAM SWE SWA 27,246 Reputation points

2024-04-25T08:06:46.42+00:00

Go to the use details in the Entra or Azure portal and take a pic of the Identities property.
PT Maliborski 246 Reputation points

2024-04-25T08:12:28.5533333+00:00