MPB Gray Screen on first Restart after El Capitan

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MPB Gray Screen on first Restart after El Capitan

Macbook pro 15", Early 2011, has been working fine. Have kept up to date with software updates.

Upgraded to El Capitan. Upgrade seemed to work fine. Used computer for about 24 hours following upgrade.

Attempted to reboot. Machine hung on reboot at Gray screen with apple logo and progress bar, progress bar did not move (waited an hour to be sure it wasn't just slow!)

Have tried various troubleshooting routines from various websites with following result:

- Reset NVRAM and SMC.

- Attempted to start in safe mode (hold down Shift). No difference from normal start

- Attempted to run Apple Hardware Test by holding down D key. Does not start hardware test. After about a minute goes to the problematic blue screen.

- Attempted to run in Single User (Command-S) and/or Verbose (Command-V) modes. Both give me the black screen indicating a Kernel Panic on CPU 0. Stack trace identifies com.eltima.SyncMate.kext as the offending check.

- Machine does reboot into recovery mode (Command-R). Have run First Aid on the disk with no problems.

- Restoring system from latest time machine did not correct the problem.

- Reinstalling OS worked, temporarily. I was able to start up the machine, go through the setup steps, use the machine for a while. However, immediately upon rebooting the machine after the fresh install, I was back at the original symptoms.

Currently reinstalling OS X (again) to try to fix. Any advice for what I can check if/when my system is up and running, or how to get past the gray screen/kernel panic issue?

Appears to be same/similar symptoms to El Capitan hangs in boot

MacBook Pro (15-inch Early 2011), OS X El Capitan (10.11)

Posted on Oct 5, 2015 1:48 PM

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Answer 1

dbwiddis Author

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Oct 5, 2015 2:40 PM in response to dbwiddis

Not a solution (yet) but this thread on dev forum indicates that old kext files which are incompatible with El Capitan may be causing problems.

Looks like getting into terminal from Recovery mode may help delete appropriate kext files... still working on my particular issue.

https://forums.developer.apple.com/message/55314#55314

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Answer 2

pjmch2

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Oct 11, 2015 5:12 PM in response to dbwiddis

I have the same problem. Please help

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Answer 3

dbwiddis Author

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Oct 11, 2015 5:26 PM in response to pjmch2

he problem is that some third party kernal extension (kext) files are incompatible with El Capitan.

Step 1: Get a verbose debug to identify the problematic kext. Hold down Command-V when rebooting, or Command-S for single-user mode. Look for the kernel panic stack trace, and find the kext causing it. In my case it was SyncMate

Step 2: Get to a terminal prompt. One way to get to the terminal is in Recovery Mode (hold down Command-R after powering on). Go to utilities, terminal.

Step 3: Hit Google with the name of your problematic kext, along with "el capitan boot" as keywords, and find the command to remove it. Many posts are on apple developer forum, use the cached view instead of logging in. In my case the command was

rm -R System/Library/Extensions/Eltima*

Step 4: Reboot. All is well.

Alternate version:

Step 1: Reinstall OS X. It works the first time.

Step 2: Type kextstat -l | grep -v com.apple

Step 3: Find where all those are in either /System/Library/Extensions, or in /Library/Extensions

Step 4: temporarily move ALL to another folder

Step 5: reboot. On success, begin moving them back one at a time from the temp folders. Repeat until you've identified and removed the bad ones.

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