We get the "Could not sign into Messages
An error occurred during activation. Try again."
The iMac is up to date with software. Late 2013 21.5" iMac.
Messages had been working well on 4 machines in the office. 2 now have this problem with no network changes.
iMac, iOS 11.4.1, messages simply stopped working
Try creating a new user account on this iMac. Log in with account and see if you can successfully log into the Messages app with your ID ... and is this ID your personal ID or one provided to you by your company?
I have already worked through each of these issues. The Apple ID works on the apple website. The iCloud email works fine. Others in my office are using messages just fine. Mine simply stopped working. The error message continues.
iMessages simply stopped working. I get the
