Monster Hunter XX - Double Cross (English Patched v4) Decrypted.3ds
If this is prepatched then that is the problem, you are supposed to dump MHXX untouched then install the pach afterwards on Citra using the
File->Install CIA... option.
I recommend that you redump MHXX properly from your 3DS using Citra’s guides at the wiki page. Then patch afterwards(not directly on the rom this time).