I am trying to install firmware.
I started with an HTC-Dev unlocked S-ON rooted stock HTC M8 (non-HK).
On the command line:
1.
C:\Users\Murad.Eagle\AppData\Local\Android\android-sdk\platform-tools>fastboot oem lock
...
(bootloader) [PGFS] partition_update_pgfs: pg1fs_security
(bootloader)...