"This account may not have an associated Xbox account" & problems with Xbox

I recently installed an update for Forza Horizon 5 and was surprised to find that I could not sign in.

"You may not proceed without being signed into a profile" even though the game had worked fine since I bought it several months ago. I had signed into my Microsoft account, created an Xbox profile, and everything was fine.

Now, I cannot even sign in to the Forza support website because I get an HTTP error to this effect. What is going on?

[table][tr][td][/td][td]"There was an error while signing you in with xbox. \nThis account may not have an associated Xbox account. \nYou may be able to resolve this by signing out and signing in again, or creating an xbox account \n- Sign out with https://api.forza.net/connect/logout \n - Create an xbox account by signing in to https://xbox.com"[/td][/tr][/table]

:)