2013-01-20 07:15:06 [SEVERE] net.minecraft.server.ReportedException: Ticking entity
2013-01-20 07:15:06 [SEVERE] 	at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:581)
2013-01-20 07:15:06 [SEVERE] 	at net.minecraft.server.DedicatedServer.r(DedicatedServer.java:222)
2013-01-20 07:15:06 [SEVERE] 	at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:493)
2013-01-20 07:15:06 [SEVERE] 	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:426)
2013-01-20 07:15:06 [SEVERE] 	at net.minecraft.server.ThreadServerApplication.run(SourceFile:856)
2013-01-20 07:15:06 [SEVERE] Caused by: java.util.ConcurrentModificationException
2013-01-20 07:15:06 [SEVERE] 	at java.util.ArrayList$Itr.checkForComodification(Unknown Source)
2013-01-20 07:15:06 [SEVERE] 	at java.util.ArrayList$Itr.next(Unknown Source)
2013-01-20 07:15:06 [SEVERE] 	at net.minecraft.server.WorldServer.getTileEntities(WorldServer.java:582)
2013-01-20 07:15:06 [SEVERE] 	at net.minecraft.server.EntityPlayer.j_(EntityPlayer.java:165)
2013-01-20 07:15:06 [SEVERE] 	at net.minecraft.server.World.entityJoinedWorld(World.java:1333)
2013-01-20 07:15:06 [SEVERE] 	at net.minecraft.server.WorldServer.entityJoinedWorld(WorldServer.java:546)
2013-01-20 07:15:06 [SEVERE] 	at net.minecraft.server.World.playerJoinedWorld(World.java:1315)
2013-01-20 07:15:06 [SEVERE] 	at net.minecraft.server.World.tickEntities(World.java:1193)
2013-01-20 07:15:06 [SEVERE] 	at net.minecraft.server.WorldServer.tickEntities(WorldServer.java:444)
2013-01-20 07:15:06 [SEVERE] 	at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:577)
2013-01-20 07:15:06 [SEVERE] 	... 4 more