21:34:53 [SEVERE] Exception in thread "Thread-6" 
21:34:53 [SEVERE] java.util.ConcurrentModificationException
21:34:53 [SEVERE] 	at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:372)
21:34:53 [SEVERE] 	at java.util.AbstractList$Itr.next(AbstractList.java:343)
21:34:53 [SEVERE] 	at org.bukkit.craftbukkit.CraftWorld.getLivingEntities(CraftWorld.java:520)
21:34:53 [SEVERE] 	at me.xXLupoXx.NoSpawn.MobCounter.run(MobCounter.java:71)