High Sierra won't install. Error message "an error occurred while verifying firmware"

@rust.kurchenko,

I had the same issues with MacOS 10.12.6 > 10.13/10.13.1 and tried every install option Google and I could come up with...Recovery/USB/App Store install attempts which failed. Apple Support lead me down the road to disk repair.

The firmware can't be verified because the EFI partition is corrupt. And DiskUtil will not fix unless run from Recovery Mode.

Ultimately, I had issues with the EFI partition on my main drive Volume (third party SSD).

I solved it by running diskutil from command line in Recovery mode against my main startup Volume.

Caution using diskutil from command line (create a backup first).

Boot from OS X recovery by holding CMD + R at the time of startup.

Once booted from OS X recovery, from MacOS Utilities app, choose Utilities > Terminal

From here, there are four steps to enter/run from Terminal's command line. I've listed the commands to execute below each step, below:

-Step 1 (from this list, find the name of your main start up drive (e.g. /dev/disk0)):

diskutil list

-Step 2 (feedback will show errors)

diskutil verifyDisk /dev/disk0

-Step 3 (which should fix the errors)

diskutil repairDisk /dev/disk0

-Step 4 (verify repair worked):

diskutil verifyVolume disk0

From here, I booted back to my Start Up drive (running Sierra 10.12.6) and launched the 10.13.1 installer file in my /Application folder. Upgrade from 10.12.6 to 10.13.1 took ~45 minutes.