Messages stopped working since Sierra Upgrade
Since upgrade to Sierra messages has stopped working.
I get this message window:
I have restarted both devices a number of times and unset and reset the neccessary messages settings.
It does occasionally seem to work sometimes but not all the time.
Any ideas?
MacBook Pro (Retina, 15-inch, Late 2013), macOS High Sierra (10.13.1), iPhone 7 running 11.1.1
