Just got a new iMac and have beent trying to get Facetime working for days. When I try to sign in with my valid Apple ID, I get the following error message:
The server encountered an error processing registration. Please try again later.
I've tried all of the suggestions I could find here and on other webistes, such as all the things listed on this site. I've also tried adding 220.127.116.11 and 18.104.22.168 to my DNS network settings. I also did everything suggested in this Apple Support document.
But I still get the above error message no matter what I do!
HELP! I need to get this working, I depend on Facetime to stay in touch with my family who live far away. I can no longer chat with them using Facetime since buying a new iMac.
I eventually talked to an Apple Support senior advisor about this, and the problem stemmed from corruption with Keychain files. Removing specific keychain entries did not work, it had to be reset back to "factory default" which means you will lose all the stored passwords for everything, but, it at least solved this problem.
Here's how to reset the Keychain:
1) In Keychain Access menu, select Preferences.
2) On the General pane there is a button that says Reset My Default Keychain. Click that button.
You should now be able to log in to Facetime and iMessage on your Mac if you were previously having problems, or if you were being prompted for the password over and over again.
Hope that helps someone.