i think i found your problem, in the image shown above your CSC is KSA(Saudi Arabia) but you are from Pakistan
you need to flash a Pakistan firmware CSC-PAK
my dear I flashed Pak version of 4.1.2 and 4.3 both. but same problem, I contacted the person who repaired the EMMC chip, he said it's board is modified now so you can not update to official firmware. he can mend it with Z3X box, but asked me not to update to official, only custom roms.