Can't sign into iMessage after updating to Sonoma
After updating to Sonoma I was signed out of iMessage on Mac (which is ridiculous, as all other iCloud services work properly, and for some reason only iMessage needed to re-sign in).
But the problems is that I can't — once I type in email/password, I get a spinner of 5-minutes long (the longest password check ever), with a 'useful' response after 'An unknown error occurred'
I've checked the password, it's correct, I log into iCloud with in on the web, so it's not a problem.
Any advice on how to get iMessage working back again on macOS Sonoma?
MacBook Pro 15″