An unexpected error occurred while updating required files mac
If you don’t have a backup system in place, I highly recommend investing in one before you install a new version of mac OS.
You can find a large number of external enclosures, drives, and SSDs, as well as a portable and easily-carried-with-you Envoy Pro EX high-performance USB 3 or Thunderbolt bus-powered SSD storage.
Before we get too far along, I want to point out the obvious: don’t install a new version of the Mac operating system without having a current backup.Normally, when you perform a clean install and erase the startup drive, you do so while running the mac OS installer from another boot drive, perhaps a USB flash drive that you have cloned the installer to.If the installer has a problem, you may find yourself forced to reboot and use the Recovery Partition or the Internet Recovery System built into your Mac.This is a similar problem to the incompatible error listed above, except it involves all Macs running mac OS Sierra and later.Just as before, start by making sure your Mac is compatible with the mac OS version you’re installing.
You can use the same links listed above to check compatibility.