So iMessage was working perfectly until a few days ago. Was not geting messages come through on the iPad or MacBook but working perfectly fine on the iPhone.
So signed out of iMessage on iPad and MacBook and tried to sign in again and keep getting 'An error occued during authentication'.
No idea what is going on.
Any clues?
Thank You
I have had exactly the same problem. Everything worked for ages prior to Sierra. Bluetooth, iMessage, FaceTime, EndNote in Pages stopped working after installing Sierra. The following procedure helped.
bluetooth: restarting the system eventually resolved this really really weird issue
iMessage: Nothing worked (including contacting apple support 3-4 times) until I zapped the PRAM (restart+cmd+option+p+r).
FaceTime: Same problem, but after zapping it appears to work now as pre-Sierra. Same solution i.e. zapping the PRAM.
EndNote in Pages: BTW, I have problem with incorrect numbering of references in EndNote with Pages too in Sierra. Needs further exploration.
It might be a bug. An update is coming soon to macOS so that might fix that problem. IOS 10.3.2 is coming out soon so that might fix the iPad imessage problem. I recommend you call Apple if the problem isn't fixed.
Ok I was in the same boat you're in. I had been searching for why all of a sudden iMessage stopped working on one laptop but not my other one. I tried every single thing on these forums. FINALLY, all I did was REINSTALL Sierra. Of course back up your stuff just in case, but otherwise THAT'S IT!! The issue with doing a TimeMachine backup and migrating your info back onto your machine is that whatever the heck was buggin out in the filesystem will just be brough right back onto the machine. I know this to be true because I spent the 16 hours backing up, reinstalling, migrating my data back on. Bam same issue. I noticed that on the 'fresh' install after I signed into my icloud account iMessage worked perfectly. As soon as I migrated my info back onto my maching iMessage stopped working. So, I reinstalled Sierra (NOT a fresh install), left my data as is. When the install was complete BAM all is well and iMessage and Facetime is working again. Hope this helps.
