I have a 2017 MacBook Pro 15″ with High Sierra. I never turn off my laptop, instead I simply put it to sleep, so next day it's easier and faster to turn it on.

But often when I wake it up the next day, it has rebooted by itself. How can I see the shutdown/reboot cause, to try to fix it?

Here is the result of command "pmset -g"

System-wide power settings:
Currently in use:
 standbydelay         10800
 standby              1
 womp                 0
 halfdim              1
 hibernatefile        /var/vm/sleepimage
 powernap             0
 gpuswitch            2
 networkoversleep     0
 disksleep            0
 sleep                15 (sleep prevented by nsurlsessiond, nsurlsessiond, sharingd, coreaudiod)
 autopoweroffdelay    28800
 hibernatemode        3
 autopoweroff         0
 ttyskeepawake        1
 displaysleep         15
 tcpkeepalive         1
 acwake               0
 lidwake              1
  • 2
    This happens to me every night. This is extremely frustrating! – IanEdington Jan 23 '18 at 15:02
  • Does it wake up with a notice saying “you shut down your computer because of a problem”? If so, possible Kernel Panic going from light to deep sleep. I had this, reinstalled and all was good, so far. – OzzieSpin Jan 23 '18 at 17:44
  • @OzzieSpin Yes, it wakes up with this message. I'll try other options before reinstall, too much work lol – delphirules Jan 23 '18 at 18:00

You can find the last shutdown cause by examining the logs. Run this command to filter the logs for shutdown causes:

log show --predicate 'eventMessage contains "Previous shutdown cause"' --last 24h

You can then lookup the shutdown cause code in this table: macOS Shutdown Causes.

  • 6
    It showed this : 2018-01-02 22:39:45.644757-0200 0xb1 Default 0x0 0 0 kernel: (AppleSMC) Previous shutdown cause: 5 – delphirules Jan 3 '18 at 22:14
  • The table says it was a 'Correct shutdown', but i did not shutdown, i just put it to sleep. – delphirules Jan 3 '18 at 22:15
  • was it left plugged in? – Mr. Kennedy Jan 4 '18 at 2:35
  • Yes, i always left it plugged. Yesterday i closed applications that could use internet connection and today the Macbook did not restarted. Will observer the next few days, thanks for your help. – delphirules Jan 4 '18 at 19:53
  • 2
    Considered an SMC reset? – OzzieSpin Jan 23 '18 at 20:35

Not exactly the same, but I had a similar issue – after some time I always found my Mac trying to close all my applications (to restart or log out, I don't know. Thanks to iTerms, which stopped this evil Mac preventing log out every time).

It was 'Log out after X minutes of inactivity' checkbox, accidentally found in

System Preferences > Security & Privacy > Advanced (in right-bottom corner)

Anyone have the same issue as I had, try checking it off.

  • Thanks! I've been having this issue for months; having time machine backups fail due to the machine logging out. – Gunther Jan 25 at 17:52

This is what worked for me

Opening the terminal and running this:

pmset -g

gave me an output of:

Currently in use:
autopoweroffdelay 21600
autopoweroff 1
... a bunch of other stuff

autopoweroff caused my computer to turn off after 6 hours (21600 sec).

running this turn off autopoweroff:

sudo pmset -a autopoweroff 0
  • Thanks, tried this but get this error : "Password: Warning: Idle sleep timings for "Battery Power" may not behave as expected. - Disk sleep should be non-zero whenever system sleep is non-zero." – delphirules Jan 25 '18 at 11:23
  • @delphirules could you post the output of pmset -g in your original questions? – IanEdington Jan 25 '18 at 14:13
  • Just edited the question and did it. – delphirules Jan 25 '18 at 16:12
  • You seem to already have autopoweroff disabled (zero). – Matt Sephton Jan 25 '18 at 16:26

Does this work for you? https://discussions.apple.com/message/32878814#message32878814

  1. Shut down
  2. Disconnect all external devices
  3. Reset the System Management Controller (SMC), repeat 2/3 times
  4. Reset the nonvolatile random-access memory (NVRAM), repeat 2/3 times
  5. Then use safeboot (SHIFT at Startup)
  6. Then reboot normally with devices disconnected.
  • Thank you! This started happening to me after the most recent High Sierra update and your instructions fixed it. – ecgak Jan 30 '18 at 3:35
  • Thanks for letting me know @ecgak. Usually, when an answer works for you it's good practice to upvote it so other can know that it's a viable solution. It also gives me the gratification of 10 points :P – IanEdington Jan 30 '18 at 14:29
  • @ecgak: I don’t think this might have fixed your problem, because this is neither a bug nor a problem, but a feature introduced with High Sierra. The problem came from the lack of communication from Apple about this new autopoweroff function. Leave your Mac on battery, put it to sleep, wait 8 h, it will shutdown. – dan May 12 '18 at 10:41
  • 5
    Never seen such a ridiculous religious receipe as "reset the SMC 2.5 times”. Apple discussions groups are haunted by Harry Potter. – dan May 12 '18 at 10:53

It looks like a bug to me. My system is restarting (according to what I can make out from the logs) due to a 'watchdog' timeout. Basically, this means that something has failed to release a resource within a defined period of time which has caused the system to 'hang' and a restart is performed to resolve the condition.


I have had the same problem for a long time.

Your sleep image is corrupted. Delete the sleep image and it should be fine.


  • While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. – grg Aug 29 '18 at 18:56

My Macbook Pro High Sierra would wake from sleep after about 10 seconds and just keep cycling. I tried all of the above and more to no avail. Then I then unplugged my new USB mouse. Problem solved.

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