graal editor problems
 

i have a offline world it's not a server but for some reason some of my levels have just become a black screen when i open them all the npcs and tiles are gone why is this happening?
sometimes when i play a level is says "failed" in the bottom right corner could that be the problem?

also when i'm playing in my world sometimes the debug or a access violation opens and graal freezes it doesn't happen too often but it's annoying anyone know why that happens?