How To Fix Error 255 In TWRP Recovery Oneplus 6 Android pie 9.0 use terminal emulator to fix the problem and delete the parallel user account.
first root OnePlus 6 then follow guide.
type su first and enter
Then give superuser permissions, then type pm remove-user 999 hit enter and reboot.
now you should be able to boot into twrp recovery and backup your phone ok fixing error 255 in twrp.#superusertechmods #oneplus6 #twrp…