error handling client message [C] AD RequestRecipeBookDestroy
java.lang.NullPointerException
        at net.sf.l2j.gameserver.clientpackets.RequestRecipeBookDestroy.runImpl(RequestRecipeBookDestroy.java:31)
        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)