Hi, I have solved this issue, the solution is changing the file jboss-service.xml under 'server\default\deploy\jbossweb-tomcat50.sar\META-INF', in this make the property 'Java2ClassLoadingCompliance' to true. This will solve the problem when you are migratining 3.x to 4.x and ejbs are throwing errors like could not dereference object. Madhu View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4058235#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...