19:01:37 [SEVERE] java.lang.NullPointerException
19:01:37 [SEVERE]       at net.minecraft.server.BlockFurnace.a(SourceFile:117)
19:01:37 [SEVERE]       at net.minecraft.server.TileEntityFurnace.g_(TileEntityFurnace.java:179)
19:01:37 [SEVERE]       at net.minecraft.server.World.cleanUp(World.java:1124)
19:01:37 [SEVERE]       at net.minecraft.server.MinecraftServer.h(MinecraftServer.java:447)
19:01:37 [SEVERE]       at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:361)
19:01:37 [SEVERE]       at net.minecraft.server.ThreadServerApplication.run(SourceFile:422)
19:01:37 [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)