[jboss-user] [JBoss Seam] - optimistic locking - exception handling

hi folks, i'm trying to use optimistic locking with seam, everything works fine except very last thing, when i'm trying to save the record (that was changed by other user) i'll get page that user can't really understand (server internal error). In jboss log i see exception(explainig problem), but at the end it comes to java.lang.NoClassDefFoundError, see log: 11:30:50,734 ERROR [AbstractFlushingEventListener] Could not synchronize database state with session org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [c om.arnie.panta.PrProdukt#21] at org.hibernate.persister.entity.AbstractEntityPersister.check(AbstractEntityPersister.java:1699) .... 11:30:50,748 ERROR [ExceptionFilter] uncaught exception javax.servlet.ServletException: Error calling action method of component with id prProdukt:update at javax.faces.webapp.FacesServlet.service(FacesServlet.java:152) ... 11:30:50,748 ERROR [ExceptionFilter] exception root cause javax.faces.FacesException: Error calling action method of component with id prProdukt:update at org.apache.myfaces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:74) ... Caused by: javax.faces.el.EvaluationException: /PrProduktEdit.xhtml @110,61 action="#{prProduktHome.update}": javax.persistence.Optimis ticLockException at com.sun.facelets.el.LegacyMethodBinding.invoke(LegacyMethodBinding.java:73) .... Caused by: javax.persistence.OptimisticLockException at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:604) ... Caused by: org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was inc orrect): [com.arnie.panta.PrProdukt#21] at org.hibernate.persister.entity.AbstractEntityPersister.check(AbstractEntityPersister.java:1699) .... 11:30:50,753 ERROR [[Faces Servlet]] Servlet.service() for servlet Faces Servlet threw exception java.lang.NoClassDefFoundError: com/sun/facelets/el/LegacyELContext at org.jboss.seam.web.ExceptionFilter.createFacesContext(ExceptionFilter.java:122) ... please give me advice how to handle this exception and show up friendly message to user on formular page. thanks pista page i get: --------------- HTTP Status 500 - type Exception report message description The server encountered an internal error () that prevented it from fulfilling this request. exception javax.servlet.ServletException: Filter execution threw an exception org.ajax4jsf.framework.ajax.xmlfilter.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:75) org.ajax4jsf.framework.ajax.xmlfilter.BaseFilter.doFilter(BaseFilter.java:213) org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96) root cause java.lang.NoClassDefFoundError: com/sun/facelets/el/LegacyELContext org.jboss.seam.web.ExceptionFilter.createFacesContext(ExceptionFilter.java:122) org.jboss.seam.web.ExceptionFilter.endWebRequestAfterException(ExceptionFilter.java:86) org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:73) org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49) org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45) org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49) org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:79) org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49) org.jboss.seam.web.SeamFilter.doFilter(SeamFilter.java:84) org.ajax4jsf.framework.ajax.xmlfilter.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:75) org.ajax4jsf.framework.ajax.xmlfilter.BaseFilter.doFilter(BaseFilter.java:213) org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96) note The full stack trace of the root cause is available in the Apache Tomcat/5.5.20 logs. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4024602#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...