I have an application in which i am using Stateful session bean problem is.. while maintaining session in 20 -30 minutes span the activation call back method is called and session is continued but if after more than one hour i came back ..its unable to start activate method and giving error JBoss/db/sessions/558392081.ser ClassNotFound error. if there is a time setting where i have to set. if container calls the remove() method for removing the secondary storage serializable object..after certain time then my remove() method in bean must called..and System.Out.P() should print .. what I did to end the session..with windowClosing(); Nothing is happening.. Please help.. thnx Sandeep