I had several problems with my Mc World in the last times Minecraft kicked me out and said: Minecraft has run out of storage. However when closing Minecraft and reopening it I could play my world just fine. I tried deleting non important things but the Problem I described happened like 3 times in the past few days. However yesterday it happend again. Now when I try to enter my World 850mb the game crashes and I just get thrown into my Xbox Menu. I cant copy the world the exact same Thing happens BUT I can export my world into Minecraft Preview and there it just works fine. So basically my World is lost and I dont know why it works on Preview and not in the Original game.

EDIT: I tested if I can put the world onto a realm that is working and I can play on it now but I cant Play it normally on the device the game crashes with purple/black texture errors.  

IMPORTANT: Uninstalling and reinstalling Minecraft made the world work again I did a backup of the world because i was scared it would get deleted but it didnt