Hello, Everything has been working great on my brand new iMac, but today, iMessages stopped synching between my iMac and iPad. It works on iPad, I can send and receive messages, but on iMac, messages do not show up. I did not make any changes to the system. I have tried all commonly suggested fixes/troubleshooting, but nothing worked. I am pretty sure that the issue has to do with Yosemite on this particular iMac and not with anything else. Why? Because I logged in to iMessages on my old iMac and everything works there. I also tried it on a virtual machine in Parallels, everything works there, too. So, it seems that there is no issue with the ID or synching itself, but it is something on this particular iMac. What could it be? As I have already mentioned, I have not made any changes at all to the system. Thank you.