I forget the device encryption password for my F5121 (locked bootloader). Is there any way to hard-reset the device, so I can use it again (I don't care about the data on it)?
I already tried some combination with Power Button + Volumne Up/Down, but I don't see any options popping up.
Also, unlocking the bootloader does not seem to work (probably I should have enabled oem unlocking in the android settings before), it says:
FAILED (remote: 'Command not allowed')
Same error, when trying to flash TWRP.