The above mentioned Macbook Pro Retina (Mid 2015) with SSD, running Sierra seems to be freezing most of the times, after attempting to "wake" it up from sleep. The situation has the following observed characteristics:

  • Seems to "wake up" (you can see the backlight of the screen activating) but the screen remains black
  • Sometimes the mouse pointer may appear but the screen remains black
  • Some times it wakes up, gives the login screen but freezes (spinning ball) after logging in
  • Happens only after some time has passed (perhaps 15') after initiating the sleep.
  • It has higher possibility to happen when connected to power
  • Thought there may be a conflict with the Energy Saver Display-off settings but keeps the same behaviour in all possible different settings including when choosing not to allow the display to switch off.

In all the above cases the system has to be hard rebooted by pressing the power button.

I would welcome any ideas on what may be wrong but also advice on where to look (log files?) to debug the situation.

  • 1
    Do you see sth suspicious regarding AppleGraphicsControl.kext/Contents/PlugIns/AppleMuxControl.kext in the (crash-) logs ? – LangLangC Sep 27 '17 at 10:47
  • 2
    A freezing after a wake is indicative of an issue with your sleep image file. Issue the command pmset -g | grep hibernatefile. It will give you the path to the file in question. Delete it. Then try to sleep/wake as you normally would (macOS will recreate the file) – Allan Sep 27 '17 at 14:23
  • Thanks to both of you! How to access relevant (crash-) logs for AppleGraphicsControl.kext/Contents/PlugIns/AppleMuxControl.k‌​ext? – George Sep 27 '17 at 14:57
  • e.g. panics wriiten to /Library/Logs/DiagnosticReports –– esp kernel panics looking like *** Panic Report *** panic(cpu 0 caller 0xffffff7fabbc7705): "GPU Panic: mux-regs 2 0 1 0 0 0 severity 3 switch-state 0 IG FBs 1 EG FBs 0:0 power-state 6 3D idle HDA idle : : GPU is not found. PCI config access fails!!! \n"@/Library/Caches/com.apple.xbs/Sources/AppleGraphicsControl/AppleGraphicsControl-3.14.49/src/AppleMuxControl/kext/GPUPanic.cpp:149 – LangLangC Sep 27 '17 at 19:53

The first things I'd try are to reset both the NVRAM and SMC in that order. Before following the steps below, ensure you have no external hardware connected (so, unplug your external display) and make sure you use the built-in keyboard.

Reset the NVRAM

Older Macs had what's called Parameter RAM (PRAM), newer Macs use Non-Volatile Random-Access Memory (NVRAM). Here’s how to reset the NVRAM on your particular MBP:

  1. Shut down your machine. Yes, a full shut down, not just logging out.
  2. Press the power button and then press the commandoptionpr keys. You have to make sure you press these keys before the gray screen appears or it won’t work.
  3. Hold those keys down until your Mac reboots again and you here the startup chime.
  4. Let go of the keys and let your Mac reboot normally.

Note: When you log back in you may need to readjust some of your system preferences (e.g. speaker volume, screen resolution, startup disk selection, time zone information, etc).

Reset the SMC

To reset the SMC on your particular MBP, follow these steps:

  1. Shut down your computer
  2. Keep the power cable plugged in.
  3. Press at the same time shiftoptioncontrol (on the left side of the keyboard) and the power button
  4. Let go
  5. Turn your computer back on with the power button.

After resetting both the NVRAM and SMC, use your computer to determine if the issue still persists.


I had this problem too after updating to 10.13.4 on a MBP Late 2013. I did a clean install and the problem still occurred. What helped for me is to switch off FileVault or disk encryption. After this, everything ran smooth again and no freezes occurred anymore. Apparently FileVault and the newer APFS don't get along quite well yet, and freezes like these are one of the symptons.


My mac kept freezing after upgrading the SSD, which forced me to upgrade to Mojave.

Resetting NVRAM and SMC didn't help for me, but I saw other threads that mentioned the hibernatefile, which is in /var/vm/sleepimage, and advised to delete it.

On Mojave, you can't delete it without de-activating SIP, but another hint said you could Eject the /var/vm/sleepimage like a DMG through the Finder.

I did that, and on reboot, a new swapfile0 showed up and I haven't had any problem since so far, so my guess is that the swapfile was missing and causing issues on wake up from sleep.

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