When I try to boot Pasta CFW from Homebrew Channel on an O3DS 4.2.0-9-US, I get "An Error Has Occured" and I am force to reboot the 3DS.
I tried re-installing Ninjhax.
EDIT: Pasta CFW 1.1.1 worked! 1.2 didn't :/
Can you try to write 000 on the system.txt and then try again to boot cfw?I get the same issue on my N3DS on 9.2J