

It might take up to 24 hours to activate iMessage and FaceTime.

If you're using an iPhone, you'll need SMS messaging to activate your phone number with iMessage and FaceTime.

Quit out of Messages, reset my computer's NVRAM, booted up in Safe Mode, log onto Messages, reboot into Normal Mode - this was a solution posted in:Ģ. Things I have already tried, to no avail:ġ. After clicking "OK", a message appears in red underneath the Apple ID sign in page: l"An error occurred during authentication." When I try to sign in with my Apple ID, I get the following alert: All of the folks I used to be able to chat with (and whose chat conversations were synced with my iPhone) now have a "-(phone number)- is not registered with iMessage" when I click on their names. I upgraded to El Capitan using Software Update, and ever since I've been unable to sign in with my Apple ID to activate iMessage. I'm running OS X 10.11 on a Mac Pro (Mid 2010, 2x2.66 GHz with 64 GB RAM).
