I am trying to install Security Update 2019-002 for OS X Sierra (10.12.6). Everything seems to work until I do the required restart. That starts out okay, but eventually, it says "5 minutes remaining" and just hangs there for hours, at which point I force restart, and the computer works fine (but the update has not been applied).
I've retried this a few times, but it always gets stuck in this same spot. I have tried installing the update both with the app store and with the DMG download available from the Apple support website. There are no error messages present.
Is there any way to diagnose and or fix this (short of a clean install)?
Best Answer
In the special case of Security Update 2019-002 for High Sierra and Sierra we might have to observe a special caveat:
Apple released an "incomplete update". What that means remains unknown in the details. But the end-result for this security update should be for Sierra, 16G1918; for High Sierra, 17G6030 in build numbers. Update failures may or may not be result of this "incompleteness".
In effect it seems advisable to not rely on the AppStore update process, but instead turn to the latest standalone installers available from Apple, for Sierra at https://support.apple.com/kb/DL1995
If installing from that DMG does fail as well, then the standard advice troubleshooting guides come into play:
After these are ensured:
Look at the Log to see if your Mac is still installing OS X
SafeMode is really misplaced at only number 5. SafeMode runs an fsck on the root volume, clears out those ever self-corrupting caches and prevents unneeded-for-the-update-installation software like extensions etc from loading.
Summary
If an update fails