
You are missing boot.firm on root of your SD. Download luma 7.1 or 8.1.1 and try it.
It worked, Thank you!Redownload Luma 7.1 and see
if that fixes the issue. It's possible your friend tried to update Luma via Luma Updater instead of going the way you're supposed to go. Can you post the contents of lumaupdater.log?