java.lang.IllegalStateException
	at net.sf.l2j.util.L2ObjectHashSet.remove(L2ObjectHashSet.java:223)
	at net.sf.l2j.gameserver.model.L2Character.removeKnownObject(L2Character.java:2990)
	at net.sf.l2j.gameserver.model.L2World.removeVisibleObject(L2World.java:452)
	at net.sf.l2j.gameserver.model.L2Object.decayMe(L2Object.java:436)
	at net.sf.l2j.gameserver.model.L2Character.onDecay(L2Character.java:724)
	at net.sf.l2j.gameserver.model.L2NpcInstance.onDecay(L2NpcInstance.java:1157)
	at net.sf.l2j.gameserver.model.L2Character$DecayTask.run(L2Character.java:396)
	at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
	at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
	at java.util.concurrent.FutureTask.run(Unknown Source)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(Unknown Source)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.lang.Thread.run(Unknown Source)