If you have a client session with one statefull bean running, and you do a redeploy of the .ear which have the same statefull bean, Jboss do the 'passivation' but when try to do the 'activation', then you have the error: 2006-08-31 04:54:53,383 DEBUG org.jboss.ejb.plugins.AbstractInstanceCache] Activation failure javax.ejb.EJBException: Could not activate; failed to restore state at org.jboss.ejb.plugins.StatefulSessionFilePersistenceManager.activateSession(StatefulSessionFilePersistenceManager.java:343) at org.jboss.ejb.plugins.StatefulSessionInstanceCache.activate(StatefulSessionInstanceCache.java:113) Caused by: java.io.FileNotFoundException: /usr/local/jboss-4.0.4.GA/server/default/tmp/sessions/StateFullBean-eriuek55-7/eriue7qe-6.ser (No such file or directory) at java.io.FileInputStream.open(Native Method) at java.io.FileInputStream.(FileInputStream.java:106) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3968608#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...