Whilst playing on the pre-release I exited the game through save and quit and left myself on the in game menu screen, where singleplayer mode and multiplayer are selectable and left for about 5 mins. after coming back and rejoining the game any newly loaded chunks would be entirely different. I tried on multiple separate worlds with the same results on each. Loading back into the world a couple times (anywhere from 3 to 7) would cause the game to freeze and close with no crash report. using task manager to close the game I was given a ticking player crash report though I do not know if this was due to forcing the game to close or is the problem itself