I have the same problem. My son booted into gateway AND updated the firmware. Both things he was not supposed to do. But he "forgot". I have old firmware backups and OTP. Basically all artifacts produced following the guide a few months ago. I tried to run SafeA9lhInstall, Luma, etc from HBL but they all hang. How can I restore a9lh preferably without hard modding?
Sorry the only way to fix is with a hardmod
To fix with a hardmod you would backup your current sysnand using a hex editor take a 8 megabyte chunk (the firm partitions) starting at offset 0x0B130000 to end offset 0x0B930000 from a old backup with a9lh already installed and overwrite it in your new backup at the same offset then flash it back to the system and you will have a fixed system that lost nothing.
After making the new backup keep a clean copy before hex editing the firm partitions in case you screw up.