I have try it but it dont work for meread the FAQ down https://gbatemp.net/threads/tutorial-downgrade-3ds-with-sysupdater.407924/ maybe it can help you
Ok i think i must Format my SD because other homebrew i download also not workdid you tried it with menuhax? if yes, i would try to format your 3ds. redownload sysupdater again, maybe download is broken. don't have another idea. keep in my mind, some users needed over 30 attempts to start sysupdater.
Yes i have do this but no works after the factory resetI mean formating your 3ds, factory reset, not the sd.
When i start the sysupdater the screen is black and down red
All other apps work from Starter
o3ds 10.3
I try it many times :/
Same problem... No fix as of yet dude, maybe JustPingo's KTM will save us