2012-11-01 10:04:01 [SEVERE] java.lang.NullPointerException
2012-11-01 10:04:01 [SEVERE] 	at net.minecraft.server.TileEntityMobSpawner.e(TileEntityMobSpawner.java:116)
2012-11-01 10:04:01 [SEVERE] 	at net.minecraft.server.TileEntityMobSpawner.g(TileEntityMobSpawner.java:85)
2012-11-01 10:04:01 [SEVERE] 	at net.minecraft.server.World.tickEntities(World.java:1192)
2012-11-01 10:04:01 [SEVERE] 	at net.minecraft.server.WorldServer.tickEntities(WorldServer.java:439)
2012-11-01 10:04:01 [SEVERE] 	at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:557)
2012-11-01 10:04:01 [SEVERE] 	at net.minecraft.server.DedicatedServer.r(DedicatedServer.java:215)
2012-11-01 10:04:01 [SEVERE] 	at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:486)
2012-11-01 10:04:01 [SEVERE] 	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:419)
2012-11-01 10:04:01 [SEVERE] 	at net.minecraft.server.ThreadServerApplication.run(SourceFile:818)
2012-11-01 10:04:01 [SEVERE] Encountered an unexpected exception NullPointerException
java.lang.NullPointerException
	at net.minecraft.server.TileEntityMobSpawner.e(TileEntityMobSpawner.java:116)
	at net.minecraft.server.TileEntityMobSpawner.g(TileEntityMobSpawner.java:85)
	at net.minecraft.server.World.tickEntities(World.java:1192)
	at net.minecraft.server.WorldServer.tickEntities(WorldServer.java:439)
	at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:557)
	at net.minecraft.server.DedicatedServer.r(DedicatedServer.java:215)
	at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:486)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:419)
	at net.minecraft.server.ThreadServerApplication.run(SourceFile:818)