High Sierra - The path /System/Installation/Packages/OSInstall.mpkg appears to be missing or damaged
Same error happened to me when I received an update from 10.13.1 to 10.13.2.

If you boot with shift button pressed, you will be able to enter safe mode and try to download and reinstall an update.
It did not help to me so I booted holding Option key and chosen regular Mac HD (not an update volume). Booted to my Mac without safe mode and tried to reinstall this update. Somehow it worked out in several reboots.