I'm not totally sure how to report this, but my world seems to have somehow become extremely corrupted and outright broken. The world is basically at a standstill, with all the entities remaining stationary, time failing to move (the sun simply bounces backwards), odd chunk loading, and the level itself crashing within minutes of startup. Crash report and level.dat file included. Also of note is the console froze with a large amount of exceptions logged, having to be shut down though the task manager.