Crashing in hall of fame

Whenever i beat [Champion Here], it crashes and displays that error message. someone please help me.

Before anyone says anything about reinstalling it,
i already did.

My friend had a similiar issue. You may not know it, but if you have a hacked pokemon, it will crash your game. Try and figure out which of your pokemon is hacked, and swap it out. Then go through the E4 again. Hope this helps!