I'm on OS X 10.11.6 with Xcode 7.3.1.
When I attempt to add my Apple ID to Xcode (Xcode -> Preferences -> Accounts), it gives me the error message:
Your session has expired. Please log in.
Try signing in again or contact Apple Developer Support to resolve account access issues.
My Apple ID account works fine for all other Apple services. I can access iCloud, the Mac App Store, the iTunes store, appleid.apple.com, developer.apple.com, etc... the only thing that's having issues with my account is Xcode.
I don't have any paid account right now. In the past (~6 years ago), I did have a paying iOS Developer account, but I let that expire after a single year.
I'm planning on calling Apple Developer Support tomorrow afternoon to see if they can help (I suspect my account might be messed up on their end), but just incase... does anyone have any suggestions for what might be the problem and how to fix this?
(I have restarted my computer and Xcode already. I've also given it several hours between tries for Apple to wrangle any server side issues. And my network connection is fine.)
This happened to me too, just today also. Turning on 2-factor authentication on my Apple ID solved it. Lame that we had to search around the net for answers though.