The game crashes when you are around too many dead zombies and players this is happening because the game is trying to preload the dead zombies and players inventory maybe remove the preload also if you have a gunfight with more than 13 players shooting in close proximity with zombies you tend to lose frame rate i suggest lowering the zombie count in large cities and spread out there spawns so in total i can reproduce the crashes, freezes, frame rate issues menu not loading when around multiple dead bodies or menu goes jittery i suggest making all dead bodies closed cases like you can close clothing etc.. except your closing the bodie this might reduce fps issues lag freezing