moop

Hi, we just tried to open up our map to play today and everything was just rendering completely wrong. Texture from the mountain was invisible, and random building were being loaded in while disappearing when we got near. Also the trader was not opening up, door was locked, despite being past 6am (And we could cheat our way in because we werent being teleported away when getting near). Does anyone know why this happens? Has anyone experienced it? Is there a possible fix? or is the savefile just ruined for good now?