External users getting UserHasNoMailboxAndNoLicenseAssignedError when trying access a booking page

[ChrisCosgrove]

I have user that has a booking page and some external users get the error code page that is attached. The issue only happens with some external users so it makes it harder for me to troubleshoot. The user has the right license and our organization policies allow external users to book.

There was another question with the same issue but it was never resolved. I'll be happy with any help troubleshooting this and can provide more information.

[#2]

Hi, we're having the same issues. Anyone got a solution?

[#3]

I had the same problem with some external users today, but not with others. Any solutions?

[#4]

The problem here is in the external account setup. This happens when the user that tries to access your bookings page has an M365 account, but exchange is not enable or licensed for that user. (maybe because they use on premise Exchange or any other provider)
You have to ask your visitor to open an browser in an inprivate mode, so that he/she is not authenticated automatically.