I have an iPad, iPhone and a MacPro (2009), I spend a lot of time in front of the MacPro so iMessage is useful to me, I can reply quickly to any text message. With Mountain Lion, 10.8 iMessage worked fine, when I upgraded to Mavericks 10.9 I lost the ability to use iMessage, I tried all the fixes I could find on all the Apple forums including deleting keychains, messing with commands in Terminal I've never used and even a clean OS install but I never got iMessage to work, over several months during a little downtime I'd spend a few hours trying to fix it, all to no avail.
So, Apple release 10.10 (Yosemite) last week and I thought this should finally fix it for me, I downloaded 10.10, installed it, all seemed fine, tried to start iMessage and got the familiar "Unable to login" - Grrr!
As Yosemite is a new release I've been watching the Apple forums for any bugs or info, one post reported a "Unable to sign in to iMessage" problem, the reply was to zap the PRAM (Opt/Cmd/P/R keys on startup), I couldn't ever remember trying this, the last time I ever used that command was way back in my Media100 days!
I tried it this morning - iMessage is now working fine with no login problems! How I ever missed that advice in all this time I don't know but all is fine now - watch this space if it changes.
UPDATE - 4/11/14
Looks like I spoke too soon, yes iMessage opened and logged in which it hasn't done for over 9 months and all appeared to be well BUT no messages, either send or receive. My iPhone would indicate a message arrive but it never appeared on the MacPro. When I realised Yosemite wasn't going to fix any of the iMessage problems I was having, I cloned back my copy of Mavericks. There was a widely reported issue with Safari by many users, it was very slow and often didn't load a webpage so I'd reverted back to Chrome to solve that problem. There were other minor performance and software issues which indicated Yosemite was never going to run as well on my 2009 MacPro as Mavericks hence the reason to 'Go back' which, thankfully was a piece of cake using the clone drive I made before upgrading.
I'll upgrade to Yosemite on my FCPX drive, that only has the system software and FCPX on it and is used solely for editing and I'm guessing, the next update of FCPX when it arrives, will require Yosemite. Meanwhile, FCP7 on a Mountain Lion drive is still as stable and fast as it's ever been.
UPDATE - 10/11/14
iMessage now working on Mavericks! Resetting the PRAM solved the logging in problem, but I still couldn't receive or send from Mavericks, resetting the keychain has now solved that problem and I finally have iMessage sending and receiving from Mavericks - it's been a 9 month long journey to get this far!
Yosemite (10.10) for Mac is now out and yes, I’ve downloaded and installed it (5.6Gb) but…..looking at the new Yosemite forum on the Apple support site, there are countless posts asking how to revert back to Mavericks!
The very first thing I did before upgrading was to clone my Mavericks install as it was, to another drive, if there were any problems or programs I needed or used not working I could do a restore quickly. I cannot understand how so many people are now hitting the forums asking how to revert to Mavericks!
A cheap 1Tb USB drive and SuperDuper (free) or Carbon Copy Cloner are all that’s needed to save hours of grief if you decide Yosemite is not for you.
I’m still kicking the tyres on Yosemite, first impressions are …… it’s very ‘flat’, I’m still on an old 4.1 Mac Pro Quad and there are are few bottlenecks and minor glitches but nothing I can’t live with. My MacPro has 4 drive bays, 1 with the new Yosemite, a 10.9.5 install with FCPX for editing and a 10.8.5 install with FCP 7 so I have the best of all options, I can try Yosemite before I load it to the FCPX drive and still have a 10.8 install with FCP 7.
Let me stress - if you want to try Yosemite, CLONE YOUR MAVERICKS INSTALL to save any problems if get them or decide it’s not for you until all the bugs are sorted!
Surprising what turns up on the Bay of E!