Two iMacs will not boot after the 10.11.4 update.

thanks davert ...

while i could most certainly both uninstall and remove any of those listed .kext files, this seems like an exercise in *hackery* and not a methodical way to troubleshoot the root cause ... and having to revert to 10.11.3 each time i've tried updating, i think the only method would be to boot to a USB thumb drive and mount up the newly upgrade, yet not working 100%, 10.11.4 SSD ...

after i'm able to mount up the 10.11.4 SSD, i would then need to know what log files to review to *hopefully* determine potential root cause(s) ...

FYI: i have logmein, parallels, and kapersky installed on the other 2 macs that updated to 10.11.4 just fine ...

Just for people like me, if you got this kind of issue, just boot in "OS X Recovery mode", and then open a terminal (Tools>terminal).

In the news terminal go to: "/Volumes/<HDD NAME>/Library/Extensions" and then remove (or move outside Library) "SUIDGuardNG.kext/".

Reboot and it's done !

1. i downloaded the latest 10.11.4 combo update (just in case it was updated/changed)

2. installed ... update appears to take, requires a restart ... performed that

3. installation continued after the reboot ... offered up the BLACK SCREEN with CURSOR (attached picture #1)

4. performed your steps ... booted into recovery mode ... changed directory to the Ext library on the HD ... SUIDGuardNG.kext does not exist

5. restoring again (time #4) back to 10.11.3

6. once the restore back to 10.11.3 is complete, i'll dump my system information and attach that as well to the posting

@tom.francen you're issue is different from mind. In my case after the initial reboot I got a Kernel Panic due to "SUIDGuardNG.kext".

If you don't find "SUIDGuardNG.kext" it's probably because your trouble is different from mine.

Renaud

I have a similar problem with my 1 year old iMac 27", it failed to start after 10.11.4 download, and will not start in safe mode either (appears to boot - reaches end of progress bar and "freezes up"). Starting Disk Utility works, but it is unable to detect any volumes or start-up disk. Therefore unable to reinstall OSX. Any suggestions?

Apole support directed me to restore my backup and wait for next update

Problem solved after discussion with Apple support: disconnect power cable - reconnect - start with alt-cmd-R-P to clear everything, then connect ethernet cable (wi-fi not good enough) - Restart with cmd-alt-R - start Disk utility which then actually found the boot volume - restart with cmd-R and then reinstall OSX

Reason for problem not really found, but procedure above solved problem.

In my case, I am unable to login after I update my Mac to OS X 10.11.4. The login interface pops up, I enter my password and then a progress bar shows up, but it is stuck at 100%.

Here is how I fixed it:

1. Shutdown the Mac.
2. Turn on Mac while pressing and holding Cmd + R to enter Recovery mode.
3. On Recovery mode interface, open Disk Utility.
4. If your drive is encrypted, click on the "Macintosh HD" from left tab, then choose File > Unlock.
5. Enter the encryption password.
6. Choose Disk Utility > Quit Disk Utility.
7. Choose Utilities > Terminal.
8. Inside the terminal window, enter the following command, press ENTER at the end of each line:
   cd /Volumes/Macintosh\ HD/Library/Extensions
   mkdir Unsupported
   mv *.kext Unsupported/
9. Choose Terminal > Quit Terminal.
10. Restart the Mac.

Yes, in case you have not noticed, I tried to move some kext (kernel extension) files into a new folder, because I suspect that these kext files are causing issues with the new OS X 10.11.4.

Hopefully it helps!

Two computers at work would fail to boot after users tried to apply the 10.11.4 update onto 10.11.3.

No SUIDGuardNG.kext present.

Maybe there's an easier fix, but what helped in both cases involves having another Mac running OS X El Capitan (that you can startup into) and a Thunderbolt cable (to connect between two newer Mac) or a FireWire 800 cable (to connect between two older Macs).

Do like this:

1. Startup the Mac that has startup problems and immediately hold down the ”T” key on the keyboard. After some seconds you should see a Thunderbolt and/or FireWire icon on the screen. This is called starting into ”taget disk mode”. More info on this here: https://support.apple.com/kb/PH10725?locale=en_USThis should make the drive of the problematic computer show up on the working Mac.
2. Just in case it might be worth running ”First Aid” on the startup drive of the problematic Mac using Disk Utility (/Applications/Utilities/Disk Utility.app).
3. Download the OS X 10.11.4 Combo Updater from Apple's website: https://support.apple.com/kb/DL1869?locale=en_US
4. Run it and apply it on the drive of the problematic computer (make sure you change the correct target driver there in the installer as it will default to the drive of the currently used Mac).

IMPORTANT: you have to have OS X 10.11 El Capitan running on the working computer, otherwise it will say that you can't run the Combo Updater since it requires El Capitan. There is a workaround for this that involves using the the software Pacifist, but I won't go into that here. 🙂

Many thanks! Its really helps!