I'm having the same problems as many of you here. iMessage was working with out a problem upgraded to 10.10.1 and for some stupid reason, I logged out of iMessage to see if I could log back in. Well, I found out I could not. Should have left well enough alone. I'm getting the same customer code over and over even after calling Apple Support. They have worked with me for about 4 hours during the past two days, knowing I have a Hackintosh. And they will be elevating the call to a higher support team. There may not be much they can do but its worth a try if they are willing to assist. They should be contacting me again in a couple of days
So if anyone here has any questions, suggestions, or trouble shooting tips I should ask or make them aware of let me know so I can relay during the call.
All you brains in the forum have always figured out a way, so its just a matter of time. Thank you all for the great work and time you have dedicated to this.
Yosemite 10.10.1
Clover
z77x-ud5h
Intel Core i5
NVIDIA GeForce 760
32 gigs RAM
Besides iMessage and FaceTime all else works: Handoff (with IOGear USB dongle), Airdrop, App Store, iCloud, Sleep, Sound (Sound Blaster USB), Trim, Network (ethernet and wireless).