Cobalt217

hello ive been trying some modifications for practice on a rom hack FE Sacred Trilogy and when i try to open the inventory it shows a black screen (on mgba) or restart the game(on visual boy advance) and when i open it on febuilder it doesn't show any errors so im confused. can someone help me fix it ? Edit: When i tried to go in combat, it crashed and said "jumped to invalid address : 01F6B998", dont know what it means