OS X 10.11.1 Macbook Pro hangs after update

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Level 1

5 points

OS X 10.11.1 Macbook Pro hangs after update

I performed the update to the latest version of El Capitan last night, now my Macbook Pro will not complete the boot process. It downloaded the update, restarted and seemed to install the update (this took about 30 minutes), then it restarted and hung with the progress bar at about 75%.

My Macbook Pro is older, model A1286, but I had installed El Cap without issues. I've tried resetting the PRAM (power of, then power on holding Command+Alt+P+R), but that had no effect. I've also tried unplugging and disconnecting the battery and holding the power button to remove any residual settings, also with no effect.

I restarted it in verbose mode and the BIOS post comes up and freezes there, seemingly before reading from the disk. The last line is "System uptime in nanoseconds: 134....." It looks like there's a kernel panic, so I'm assuming the update changed some kernel drivers that have hosed my system. Does anyone know what can be done about this?

I've included a screenshot below.

Thanks!

MacBook Pro (15-inch Early 2011), OS X El Capitan (10.11.1), 8GB Memory, 500GB SSD

Posted on Oct 22, 2015 11:15 AM

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Answer 1

Oct 22, 2015 11:33 AM in response to appLeslie

Luckily I have a copy of Yosemite on my macbook pro 1286, previously I swapped the superdrive with a 1 TB disc and kept the original 500gig drive. When funds allow Ii'll get a flash HD El capitan is on the 1TB drive and Yosemite on the 500 gig drive. After installing El capitan, the mac wouldn't start up but just hung.. I then restarted holding down alt key and selected the other start up disc- it starts up fine. However, although I've had macs for 30 years I'm no expert. Not sure this 'update' is worth the hassle but I need to get my mac working smoothly again. It starts up fine in target disc mode to by the way. I ran disc utility and repaired permissions etc,. Is there a cure for this issue? Problems like this are very time consuming!

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Answer 2

Oct 22, 2015 12:00 PM in response to appLeslie

I'm having a problem similar to yours, however when I tried to reboot in single user mode I got this error

BuildUser() : error buildng a user of type 0x20010008

and then it booted up normally. From what I can tell from searches the above error is related to FileVault.

Unfortunately, I'm getting the same bar on login which hangs at around 75% and then I get a prohibited symbol on a black screen. I'm currently using recovery mode to reinstall in hopes that this is the problem

Macbook Pro retina 2012(?) with 500 gb SSD, etc.

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Answer 3

Oct 22, 2015 12:53 PM in response to Peter Hanley

I've just reinstalled el capitan from my boot disc and it started up as it should, not sure if it's sorted totally as yet Peter.

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Answer 4

appLeslie Author

Level 1

5 points

Oct 22, 2015 3:14 PM in response to appLeslie

I've found similar posts about the culprit being eltima syncmate, the kernel plugin doesn't work with El Cap. http://apple.stackexchange.com/questions/211011/how-to-fix-syncmate-kernel-panic -at-el-capitan-boot

I've deleted the kext from the system, but it still fails at startup. The link talks about the same failure still occurring because of the kexts having been compiled and cached and that the caches need to be removed, but it doesn't seem to make a difference. I've tried removing the kext and every related cache I can find, but it still loads it and still kernel panics on it...

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Answer 5

appLeslie Author

Level 1

5 points

Oct 22, 2015 3:13 PM in response to appLeslie

My problem was that I had a bad kext that was causing a kernel panic. There are plists that explicitly say not to load it, but I'm guessing that since it was already pushed into the prelinked kernel, it was getting loaded anyway and causing the kernel panic. So here's how I fixed my problem:

Boot into recovery mode with Command+R
Open a terminal window. Utilities -> Terminal Window
Navigate into the start up drive
cd /Volumes/{start up drive volume}/
Remove the offending kext (mine was called Eltima.SyncMate.kext)
rm -r System/Library/Extensions/Eltima.SyncMate.kext
remove all kext caches
rm -r System/Library/Caches/com.apple.kext.caches
Remove any hibernation or quick restart related files
rm var/vm/sleep*
If you have file vault on, remove all file vault relates caches
rm var/folders/*
Rebuild the prelinked kernel file and prelinking caches. This was the crucial step that I was not really finding a solution to elsewhere.
- kextcache -update-volume /Volumes/{start up drive volume}
- kextcache -prelinked-kernel System/Library/Caches/com.apple.kext.caches/Startup/kernelcache -K System/Library/Kernels/kernel System/Library/Extensions
- If the above command doesn't work, because of other invalid kexts you can add -s to only build this with the mandatory start up kexts
  kextcache -prelinked-kernel System/Library/Caches/com.apple.kext.caches/Startup/kernelcache -K System/Library/Kernels/kernel -s System/Library/Extensions
Restart the system
At this point it should boot up and everything should seem fine. I didn't like the way I had to rebuild the prelinked kernel so I rebooted back into single user mode to rebuild it properly. Reboot and hold Command+S
Follow the instructions for mounting the root partition as read/write.
Rebuild the prelinked kernel file by forcing kextcache to see the extensions as having changed
- touch /System/Library/Extensions
- kextcache -system-prelinked-kernel
Reboot

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