Typically after being closed for a few hours, overnight, etc, I open the laptop and get this horrid grey screen for probably 5 minutes. When it does come back the UI is locked for another minute or so. Why would it decide to start doing this only recently?

enter image description here

I've checked hibernate mode, which was set to 3. I changed it to 0 and that made no difference. Still grey screens me every morning.

MacBook Pro (13-inch, Mid 2012)

2.5 GHz Intel Core i5

16 GB 1600 MHz DDR3

Intel HD Graphics 4000 1536 MB

Disk space is about 50% used. Battery fully charged and still in good shape. Laptop is pretty much always plugged in. Full charge lasts all day, so I don't think it's a power issue. I have clean my mac constantly profiling the machine, which reports not even half RAM usage at wake up, and across the board very low consumption.

Starting to get pretty annoying. It never did this until recently, about 4 months ago. I usually keep my OS a version behind on purpose, fyi. Anyone else know what this is and how to prevent, disable, or correct it?

2 Answers 2


What you're seeing is to be expected if your Mac is waking from what's called Safe Sleep.

Safe Sleep is a protective measure used by your Mac to ensure any data stored in memory isn't lost when your Mac shuts down due to a flat battery.

My guess is that the reason this only started about four months ago is that either:

  • the overall condition of your battery has changed
  • the power adapter has developed a fault
  • the way you leave your Mac at night has changed

In other words, for some reason, starting four months ago your battery is being drained to a level that data stored in your memory will be lost because your Mac is going to shutdown. So your Mac is going into Safe Mode to save all this data to your drive.

When it wakes up, you'll see the grey screen and progress bar that appears after Safe Sleep.

You can read more info from this Apple support article.

Now, in your question you state:

Battery fully charged and still in good shape. Laptop is pretty much always plugged in. Full charge lasts all day, so I don't think it's a power issue.

If you're absolutely certain of this, and have no reason to suspect a faulty power adapter, then I would reset your System Management Controller.

Reset the SMC

  1. Shut down your MacBook Pro
  2. Unplug the power cable from your Mac
  3. For 10 seconds, press and hold at the same time the shiftcontroloption keys (on the left side of the built-in keyboard) and the power button
  4. After 10 seconds let go of all keys and the power button
  5. Plug in the power cable
  6. Turn your Mac back on with the power button.
  • Is there a terminal command or something I can run to verify the SMC has been reset? I went through the process but aside the machine not turning on when holding all buttons I am not sure how to know it took effect. As for the power cable - I suppose there are things I may not know, but it has no issues charging the laptop, registering it is connected, etc. Appears to be operating same as the day it was bought. I'll leave it tonight same as usual and see if it does it again tomorrow. Next night I'll try leaving it unplugged to see if somehow the cable is causing a false positive for something
    – Kai Qing
    Commented May 9, 2017 at 2:26
  • I wish there was - I've certainly never come across one (i.e. a Terminal command). The only way to confirm it was successfully is to check that all systems controlled by the SMC work properly (e.g. you can put the MBP to sleep, you can wake the MBP from sleep by a press of the power button, the fans are running as they should, and so on. As an aside, after a couple of days testing, let me know how you go. We can actually test for a faulty sensor etc if we need.
    – Monomeeth
    Commented May 9, 2017 at 2:41
  • Ok so I think you got it. It has to be the power cord somehow. When left overnight with no cord attached, it woke up fine, battery was still full, no grey screen. I put the cord back in, left it a couple hours, came back, grey screen, took forever to wake up, battery was still full. Did another round without the cord, woke up fine. So basically, who knows which end it is on, but something about it being plugged in when sleeping is triggering this backup process. I guess I'll buy a new cord and see if it's that. Hopefully it's not on the laptop itself. Thanks!
    – Kai Qing
    Commented May 11, 2017 at 2:09

You can turn off Safe Sleep (hibernation)

From a Terminal, use the following command to disable hibernation:

sudo pmset -a hibernatemode 0

If you later want to enable hibernation, use:

sudo pmset -a hibernatemode 3

If you want to free up the disk space used by hibernation, use the following command:

sudo rm /var/vm/sleepimage

Note: This file is automatically recreated as needed if hibernation is reenabled and it doesn't already exist.

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