error handling client message [C] 17 TradeDone
java.util.ConcurrentModificationException
        at java.util.AbstractList$Itr.checkForComodification(Unknown Source)
        at java.util.AbstractList$Itr.next(Unknown Source)
        at net.sf.l2j.gameserver.model.Inventory.getItemByObjectId(Inventory.java:690)
        at net.sf.l2j.gameserver.model.PcInventory.getItemByObjectId(PcInventory.java:73)
        at net.sf.l2j.gameserver.model.L2TradeList.tradeItems(L2TradeList.java:230)
        at net.sf.l2j.gameserver.clientpackets.TradeDone.runImpl(TradeDone.java:74)
        at net.sf.l2j.gameserver.clientpackets.ClientBasePacket.run(ClientBasePacket.java:56)
        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)