Well that is not fun… You know that you typed your password in correctly. You are certain of your username, and there is no good reason why… unless they changed something? Hmmn… let’s log in with our local account again (remember, the one you were logged into to connect to the AzureAD in the first place.
In the Settings window, select Accounts. Once there, navigate to Other users.
So technically, according to this screen, you should be able to log into the machine as AzureAD\MitchGarvis. Well guess what? You can’t. I can tell you right now that I have AzureAD accounts with that name under at least a dozen Azure tenants… and even if I didn’t, there is nothing stopping anyone from creating an account with that name (not that anyone would want to be me, but you understand what I am saying).
So that won’t work… but herein lies a clue as to the actual solution. Try this:
This may be a few extra characters, but it is a small price to pay for using the same datacenters as tens of millions of other users. Add the prefix AzureAD\ before your account name, and it will let you in.