failed to sign in with my Apple ID to activate iMessage on Mac OS 10.12.3
I failed to sign in with my Apple ID to activate iMessage on Mac OS 10.12.3. But ironically, I could sign in at my iPhone and iPad. I could also login to my iCloud using browser. This is only after I updating OS yesterday to the latest version.
MacBook Pro (13-inch Early 2011), macOS Sierra (10.12.3), no comment.