Is anyone else having a problem with a complete system freeze after Mac wakes from sleep mode? Post OS X Yosemite install.

Try clicking on Mail and it should sit there and bounce up and down with a spinning beach ball. Then right click on the Mail icon and Force Quit. Open Safari and the menu bar will appear. If the desktop icons, like the HD do not appear, quit Safari and they should pop up.

MY air froze during the install w 15 min to go. I cannot do anything.

Wait a bit. It took about an hour for mine to finish.

I am having the exact same problem. Also setting computer sleep to never which is working for now. Looking forward to hearing how they resolve this problem.

Late 2012 Mac Mini

I have set my sleep to never also, but I also found that if you go to key chain and put the keychain icon on the menu bar, that you can lock the screen from there and the log in works every time. I don't know all that it does, but it does make my monitor shut down when I do this, just like it does when it sleeps. Will be glad when they get this fixed!

Hey runningoutofnames...Can you report back on this thread on whether your Keychain solution consistently works, especially when you put your Mac to sleep for a couple hours (if not overnight)? I turned off all sleep options (computer and display) and had planned to manually put the computer to sleep and see if it'll wake up after a couple hours. If not, I'll assume Keychain sleep is different than Apple menu sleep. Thanks for proposing a workaround...

This has worked consistently overnight, and each and every time I need to get to my computer ever since I did this. I do not know if the computer is actually asleep or not, but it does cause my monitor screen to go black and come up with the "No signal Message", then the monitor turns off, just like it used to when being put to sleep.

That's my experience, too. Given that putting my Mac mini into "lockdown" (my term) via Keychain, I can tolerate running Yosemite enough to wait out the inevitable dot maintenance release. It just means I need to remember to lock the machine instead of having Sleep and Energy Saver settings do the work. And my memory isn't as stellar as Mac's.

Same here. I have a Late 2012 Mac mini, reinstalled Yosemite but the problem remains. As a temporary solution, in System Preferences I prevented it from sleeping.

Exactly the same, Mac mini (late2012)

I am going back to 10.9.5 (from TimeMaschine). There it is OK!

Same here on my mini. Freezes the screensaver screen. Mouse moves, but no login window. HELP!!!

I'm having exactly the same problem, 2012 Mac Mini. Never froze before installing Yosemite, now freezes each time it wakes from sleep. I have set it so that it never sleeps and will shut it down overnight until Apple find a fix.

Exact same thing here - and it's been persistent since the first Yosemite beta. I've sent numerous tickets for this. I'm afraid Apple is too busy futzing with iPhones and iPads to be too concerned about a few users who are having these persistent problems.

Luckily, I put yosemite on its own drive, so it's easy to go back to something that works.

Yours in beta testing forever…

Hard reset and restart is the only thing that works. (or shutting down every time you leave your mac)

Just add my name to the list. Late 2012 Mac Mini, freezes consistently after waking from sleep and can't be woken up or shut down with the keyboard or mouse, only power button. Mine is a completely clean install of Yosemite with user documents migrated back using Migration Assistant. Wish I could say I plan to revert to Mavericks from Time machine, but on Mavericks when I woke it from sleep it would have a black screen with a rainbow beach ball, cursor, or no response to the keyboard waking it up. I did a clean install to get rid of the Mavericks issue. Now I can't decide which I would rather live with. I'll be filing a bug report, and I just hope Apple pays attention to us late 2012 mac mini users, instead of giving us a flip answer like "buy a new one."