Q: with 10.11.2, Mac Pro 2013 will not wake up 4k displays after sleep like before.

The thing that is most frustrating about this is Apple pushed 4k/HiDPI displays so hard in their marketing for the 2013 Mac Pro. Then they never released a first-party display of their own. Then they outright break 3rd party display support.

When I first saw the Mac Pro, I thought maybe they were re-committing to the Pro market segment. These days, I certainly don't feel that way.

I'm dealing with the same issue, though I turned on Filevault, and I can't get the Mac Pro to display anything on the 4K monitors at this point. It does work fine on my 14 year old 1600 x 1200 monitor, though I can't really work on this.

For me this has been one of the worst Apple bugs in years, it made my Mac Pro pretty much unusable for the past 20 days. As it's been Christmas I've been getting away with mainly working from my MacBook Pro, but today I decided to try reverting to 10.11.1 as I need to get back to full productivity. I already had the App Store installer for 10.11.1 backed up on a drive, so used that with DiskMaker X (http://diskmakerx.com/) to create a USB install drive. Booting from that I was able to install over the top of 10.11.2 without any issues. Hassle, but having everything back working was worth it. Hope that helps someone!

> For me this has been one of the worst Apple bugs in years, it made my Mac Pro pretty much unusable for the past 20 days

Hear, hear.

I'm less annoyed by the bug itself—okay, maybe not, this is pretty awful—than I am with the fact that we have gotten zero communication from Apple on this issue. These are $3,000–$10,000 computers. What on earth is happening to Apple's OSX/Mac division?

The problem is not solved

Also having this problem with 2013 Mac Pro with dual Samsung U590's. I have found that forcing the monitors to wake by going through menus and changing input + spamming CMD + F1 and CMD + F2 can get them to wake.

Very glad that I am not the only person having this issue. Thought my Mac/Monitors actually had a hardware issue. Don't worry guys, as long as we make Apple aware of the problem it will get fixed.

Filled a bug report (which everyone here should do).

Ok I found a pretty reliable method of getting my monitors to wake up. So far it has worked 100% of the time for me.

1. Wake computer by shaking mouse, clicking, tapping keys, whatever. Wait a couple seconds.

2. Log in blind. If you only have one account it's pretty easy, just type your password and hit enter. This may be difficult depending on your setup.

3. Spam CMD + F1 and CMD + F2 back and forth until monitor wakes up. Should take a few seconds.

There you go! This method literally has saved my Mac Pro for me. The unplugging/replugging method was getting rather unreliable and the unnecessary wear and tear of it was bothering me. I also didn't like the leaving my computer and monitors on 24/7 either.

Thanks @CodedGames!  I've used your method no less than 20 times without fail, it has worked every time. 

Thank you!

It is not working for me.

It works for me if I keep hitting cmd-f1. Doesn't work if I toggle between f1 and f2

Note: Make sure you have your f keys disabled without hitting the fn key. You can check by going into keyboard settings and verifying "Use all F1, F2, etc. keys as standard function keys" is unchecked.

I got an email from Apple saying the latest 10.11.3b possibly fixes this issue. Willing to bet some of you have received one as well.

Looks like 10.11.3b2 has fixed this issue for me.

I to can confirm that the latest beta (build 15D13b) appears to have fixed this problem.

Well, it worked, then it didn't.

beta 2 10.11.3 worked for me. Fixed wake up issue. Using MacPro and Samsung U28E590 Display.

Will report the overnight wake up tomorrow am.