I have a massive room for spawning monsters in and it has a "light switch" that controls the ceiling (which is mostly redstone lamps) and after turning it off, the lighting has to be manually updated everywhere, and it takes a very long time. first screencap is the lights on, second is the lights off, and third is about 10 minutes work on updating the lighting.
Please force a crash by pressing F3 + C for 10 seconds while ingame and attach the crash report here.
Please zip (or 7z) the world and attach it to this ticket.