Minecraft wiki entry for Crash, associated text: Crashes are unexpected shutdowns of Minecraft. When Minecraft crashes, it typically closes immediately, though it may show an error report marking the location of the exception that caused the crash. A sign of a server crash is a "Saving chunks" or "Shutting down internal server" screen. The most common cause of crashes are mods, preexisting bugs, and updates. Attempting to modify the files of Minecraft or individual worlds, even with advanced editors, can also cause crashes. Crashes can also be caused by bugs in the game. Crashes can sometimes cause the corruption of save files if the player is not careful enough. Because of this, it is highly recommended that the player regularly keeps a copy of their save folder (located in the %appdata%\.minecraft directory on Windows systems or ~/.minecraft/ in linux and also <username>/Library/Application Support/minecraft on Mac), to reduce their losses should a world become corrupted as a result of a crash. Large TNT explosions can also cause crashes.