java.util.ConcurrentModificationException
        at java.util.WeakHashMap$HashIterator.nextEntry(Unknown Source)
        at java.util.WeakHashMap$ValueIterator.next(Unknown Source)
        at net.sf.l2j.gameserver.model.L2Attackable.calculateRewards(L2Attackabl
e.java:570)
        at net.sf.l2j.gameserver.model.L2Attackable.doDie(L2Attackable.java:485)

        at net.sf.l2j.gameserver.model.L2Character.reduceCurrentHp(L2Character.j
ava:2854)
        at net.sf.l2j.gameserver.model.L2Attackable.reduceCurrentHp(L2Attackable
.java:456)
        at net.sf.l2j.gameserver.model.L2Attackable.reduceCurrentHp(L2Attackable
.java:398)
        at net.sf.l2j.gameserver.model.L2Character.onHitTimer(L2Character.java:4
126)
        at net.sf.l2j.gameserver.model.L2PcInstance.onHitTimer(L2PcInstance.java
:2030)
        at net.sf.l2j.gameserver.model.L2Character$HitTask.run(L2Character.java:
249)
        at java.util.concurrent.Executors$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)