Hello,
I have a GT-I9505 jflte device. I have used many custom ROMS but recently I updated my bootloader and modem from XXUEMK9 to XXUGNH8 (4.4.2). Thing is my device / region stock firmware only goes up to 4.3 XXUEMK9 and because the bootloader can not be downgraded I am unable to flash back...