My Mac laptop is freezing like age old windows laptop since I have upgrade my mac os to mac os high sierra.

Mac details : Mac book pro retina mid 2012

It just freezes and i am forced to restart my laptop, (it never ever happened before) Is any one facing this problem, how to fix it ?

Steps done :

  • Run complete diagnostic test
  • Reset smc
  • Reset nvram from this link

I was faced with the same dilemma, it seemed like my MacBook Pro (mid-2015) was 'freezing.' I stumbled across a the fix to it after seeing your post - you can read about it here: https://jrgarrigues.github.io/2017/11/05/high-sierra-freezing/

The gist of the linked article is this:

Reset your NVRAM and the SMC [System Management Controller]

First reset your NVRAM.
Turn off your Mac. Then turn it on and hold Command+Option+P+R while the computer is booting up. You will hear two chimes or on newer MacBook Pro models you will see the screen come on and go off twice.

Now, shut your computer down again and reset the SMC [System Management Controller].
With your Mac off, press Shift+Control+Option and then hold these keys while pressing and holding the power button for 10 seconds.

  • 1
    Does this really fix the problem?
    – Ali Gajani
    Apr 12 '19 at 0:29

The first rule of troubleshooting, "isolate and identify." In other words, if you have added any hardware to your Mac over the years, remove it. I have seen RAM now recognized as "bad" by a new OS where it worked fine with the previous OS.

The comments about Safe Mode also apply as that disables third party additions to your computer. Hold down SHIFT while booting, when the Apple logo appears release shift. Booting takes longer in Safe Mode, let it do it's thing. If your Mac stops freezing then something you installed is broken under the new OS.

The 3rd thing I would try is one of the OS "cleaning" tools. I use Onyx (there are others, that's my favorite). Download it, and run the automation tool, then reboot your Mac.

Let us know the results by editing your question to indicate what you have tried.


I was having the same issue on High Sierra 10.13.3 after I migrated my system to an external SSD with APFS formatted as a BOOT DRIVE. Since the migration, I get lots of freeze and restart issues after an hour of usage or not waking up from sleep. After running ONYX (the latest), its been running like a charm, no issues so far after 14 hours of usage and switching between multiple applications.

  • First try Running Onyx (Free download) maintenance Script if that doesn’t solve the problem, then:
  • Second, go into recovery mode (Restart, then press Command R until you see the apple logo) and reinstall High Sierra, this may correct some issues with the OS.

Not sure what your model you have but I hope this helps someone. So for me I had an intermittent freezing even after performing restores several times and replacing the hard drive. I was getting an intermittent prohibitory sign basically a circle with a line through it. The resolution was replacing the hard drive cable. I couldn't believe it but the whole time it was the hard drive cable. I would suggest ruling out software issues by just performing a simple reinstallation of the OS. If that doesn't work more than likely your issue is hardware related. I replaced the hard drive still same issue replaced the cable all good now


This is about nsmb.conf file: https://developer.apple.com/legacy/library/documentation/Darwin/Reference/ManPages/man5/nsmb.conf.5.html


Add the below to your /etc/nsmb.conf file. It fixed the problem for me.


Source: https://support.apple.com/en-ca/HT205926

  • 3
    What are these lines doing? It looks a bit suspicious to me. signing_required=no, streams=yes, file_ids_off=yes...
    – Stophface
    Jan 26 '18 at 13:32
  • What does this change, for which service/daemon?
    – nohillside
    Jan 26 '18 at 15:11
  • There's no documentation for this file anywhere in Internet (but this post). Please add more information or remove the answer. Feb 6 '18 at 6:07

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