so i got the nerve to try downgrading my ultra with fastboot since rsd won't detect my phone when it switches to fastboot using this tutorial http://forum.xda-developers.com/show....php?t=2580060
all went well except on the mfastboot command i got this responce
0140321\sdk\platform-tools>mfastboot flash system system.img
(bootloader) Variable not supported!
target max-download-size: 768MB
sending 'system' (574208 KB)...
OKAY [ 36.243s]
(bootloader) Preflash validation failed
FAILED (remote failure)
finished. total time: 59.547s
and it said on the screen mfastboot error invalid piv image size for system
now the phone won't boot just jumps right back to the bootloader screen
tried it 2 more times and still no joy same out come so what do i do now? download the file again and try once more . and do i need to repeat all the steps b4 this command or will just running this command alone be fine to fix me HELP pls