Same issue here, tried twice and issues both times - MacBook Pro Late 2011.
First try installed security update fine, loaded into OSX, however App Store was still showing the security update is required. So rebooted, however it came up with the installation error log after the chime and loading bar was showing. Can’t remember exactly what it said, but I selected the start up disc here. After a couple of reboots it booted into OSX again fine and was still showing the update.
So tried again second time, this time using the link from the Apple website for the security update. Apple site said the update is 411mb but actually 1.8GB file downloads. Again it installed fine and booted into OSX. This time App Store showed the update had installed successfully and no updates required.
So tried to reboot again to check it still boots up ok, and hit the issue this time again, but worse. After the startup chime and loading bar gets half way, it just get a white screen with no entry sign. Option boot wouldn’t show me any other start up discs, only MacHD. So I was left with having to time machine restore. After this the update is still showing as required!
Any ideas what to try next?
Would the sequence of commands posted earlier solve this? When exactly do you run the commands? After the installation has completed successfully, and before you try to reboot manually. Or before you start the installation?
Any help would be appreciated - thanks!