Can’t install Mojave. Need a new disk?

  • I get a can’t install error - Run First Aid…
  • First Aid doesn’t work
  • Booted into recovery mode and first aid doesn’t work
  • Boot into single user and try a couple of fsck-fy’s And no go.
  • I get a file system check exit code 8
  • I made a bootable USB with same outcome.
  • High Sierra boots up no problem
  • I am double backed up.
  • Will an erase in recovery mode and clean install solve this, or is my SSD trying to die on me ?


I needed to do a clean install from a USB bootable updater and the APFS re-wrote correctly.
All is well. Now to wrestle with all the update bugs that the app developers need to squish

If its an older Mac did you check its compatible with the system requirements for macOS 10.14 Mojave?

Nah. It is a 2017 MBP 13” Touch Bar.