Some Mac users have reported installation failures when trying to install MacOS High Sierra 10.13.4 update, usually seeing an error about the installation not being able to complete. Sometimes the installer freezes after many hours of being stuck, or sometimes the update seems to install but the Mac refuses to boot as usual afterwards.



If you have encountered an error or a failure when trying to update macOS 10.13.4 system software, you may be able to easily correct the problem by running through the troubleshooting steps detailed below. We’re going to focus on two main approaches; running the update again (if it’s a general failure upon attempting to install from the App Store) or by trying to install macOS 10.13.4 with the macOS High Sierra 10.13.4 Combo Update package instead of through the Mac App Store, or simply choosing to reinstall macOS system software.

Before beginning any of these troubleshooting steps you should have a complete backup made of the Mac. Ideally you’d have made a backup before installing the system software update to begin with, which then allows you to roll back to that prior backup in the event neither of the following approaches work to resolve the problem.

If the Mac boots as usual, try the Combo Update

If installation fails but the Mac is still usable as normal, try running the 10.13.4 Combo Update:

The Combo Update can be installed directly atop a prior macOS 10.13.x version.

Using combo updates to install Mac OS updates is pretty straight forward process, similar to running any other application installer. The Mac will reboot when updating has completed.

If the Mac won’t boot as usual, try reinstalling Mac OS through Recovery Mode

If the Mac will not boot, you may need to reinstall Mac OS through Recovery Mode:

Reboot the Mac and hold down Command + R keys to boot into Recovery Mode

Choose “Reinstall macOS” from the macOS Utilities screen

Reinstalling macOS will just install a new copy of system software, it should not change any user files, applications, or data aside from system software. Nonetheless it’s critical to have a backup of your data available just in case something goes haywire.

Reinstalling Mac OS X through Recovery Mode is a tried and true troubleshooting approach for situations where the system software will not function as intended or won’t boot at all.

If all else fails, you can try restoring the Mac with a backup made from Time Machine to a date prior to installing 10.13.4, assuming you made one anyway (one of the many reasons regular backups are so important!).

Installation failures and software update failures should drive home the importance of always backing up a computer, particularly before installing any system software update, security update, or other software.

After macOS High Sierra 10.13.4 successfully installs, you can get a Security Update 2018-001 for macOS 10.13.4 as well, but don’t forget to backup before beginning that process either.

Did these tricks work to resolve your problems installing macOS 10.13.4? Let us know in the comments below if these approaches worked for you, or if you found another solution.