What is the oddest, weirdest, or strangest bug you've encountered

One of my own games, Dungeon Diver 4, had a weird bug at the time of release that I can no longer reproduce, making me suspect it was a bug in an older Java 8 version... anyway, when you landed the killing blow on an enemy in battle, the game would sometimes play the "death" sound continuously for about 1.5 seconds then crash. (Yes, this was one of those bugs that could be VERY loud if it triggered.)