The way I solved my daughter's "iMessage Activation" error
Writing these notes in case they help someone. My daughter recently tried to add her Apple ID to her iPhone'sApple Messages app. (Settings > Messages > Send & Receive > Add Apple ID) When she tried this, she got a dialog box where she could type in her Apple ID and password. After a 15 second delay she got an error dialog box: iMessage Activation An error occurred during activation. Try again She got a similar error message if she tried to activate FaceTime: FaceTime Activation An error occurred during activation. Try again I searched the Internet, and tried the various remedies that Apple and others suggested: Reboot Phone. Make sure the phone can receive SMS messages. Enable/disable iMessage and FaceTime. Log the iPhone out of iCloud and log back in again. Visit icloud.com and check the iCloud account to see if there's any warnings or errors. Update the phone OS to the latest re...