I've recently been trying to flash twrp on my Lg Aristo 2, when I ran the code to OEM Unlock a device it came out with the same "FAILED (remote: 'unknown command')". I started my phone back up and it came to a set up screen, I set up my phone and it said it was OEM Unlocked. When I try to flash a custom recovery, or run any command with fastboot at the beginning i get "FAILED (remote: 'unknown command')" and it doesn't work. Can someone please help?
Seems fastboot is broken or disabled since Oreo.
First you have to downgrade ROM to Nougat. You can flash *.KDZ files with LGUP or LG Flash Tool.
Then it should work as usual:
- Make sure you have enabled
System Settings > About Phone > Developer Options > Enable OEM unlock, and
System Settings > About Phone > Developer Options > Enable USB debugging
check adb is working
check fastboot is working
adb reboot bootloader fastboot devices
WARNING: Factory reset, all data lost!
unlock the bootloader (one of these should work)
fastboot oem unlock fastboot flashing unlock
if unlocking was successful, you can test recovery without flashing
fastboot boot <path>/recovery.img
then reboot into bootloader and flash recovery
adb reboot bootloader fastboot flash recovery <path>/recovery.img