When I am using my developer account, I am getting this message in Xcode 8.
Your session has expired. Please log in.
With another Apple ID it works. Also when logging in to developer.apple.com everything is okay; I log in without a problem. How can I fix this?
I just added two factor authentication to my Apple ID and Xcode was fine again. Don't know how it's related but it worked for me. Do the same.