Code: 2011-07-13 20:20:31 [SEVERE] at net.minecraft.server.BlockFurnace.a(SourceFile:117) 2011-07-13 20:20:31 [SEVERE] at net.minecraft.server.TileEntityFurnace.g_(TileEntityFurnace.java:179) 2011-07-13 20:20:31 [SEVERE] at net.minecraft.server.World.cleanUp(World.java:1124) 2011-07-13 20:20:31 [SEVERE] at net.minecraft.server.MinecraftServer.h(MinecraftServer.java:447) 2011-07-13 20:20:31 [SEVERE] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:361) 2011-07-13 20:20:31 [SEVERE] at net.minecraft.server.ThreadServerApplication.run(SourceFile:422) 2011-07-13 20:20:31 [SEVERE] Unexpected exception java.lang.NullPointerException at net.minecraft.server.BlockFurnace.a(SourceFile:117) at net.minecraft.server.TileEntityFurnace.g_(TileEntityFurnace.java:179) at net.minecraft.server.World.cleanUp(World.java:1124) at net.minecraft.server.MinecraftServer.h(MinecraftServer.java:447) at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:361) at net.minecraft.server.ThreadServerApplication.run(SourceFile:422) This crashed the server just now. Any ideas on the cause?