Unable to log in to iMessage, unknown error

1. Restart your device. This can often fix minor software glitches.
2. Check your internet connection. iMessage requires an internet connection to work. Make sure you're connected to Wi-Fi or cellular data.
3. Sign out of and back into your Apple ID. This can sometimes fix problems with your Apple ID account.
4. Reset your network settings. This will reset all of your network settings, including your Wi-Fi network passwords.
5. Update to the latest version of iOS. Apple often releases software updates that fix bugs and improve performance.

Contact Apple Support. If you've tried all of the above and you're still having problems, contact Apple Support for help.

Here are the steps on how to reset your network settings:

1. Go to Settings > General > Reset.
2. Tap Reset Network Settings.

Enter your passcode and tap Reset Network Settings again.

Your device will restart and your network settings will be reset. You'll need to reconnect to your Wi-Fi network and enter your password again.

If you're still having problems after resetting your network settings, you can contact Apple Support for help.

Messages are working now but I had to restart in Safe Mode to get it to work. All is good now!

Me too, BearsTooth. Have you had a chance to try Jijo suggested?