Hi. I was also getting this error. I solved this error by copying javaee.jar to C:\jboss-4.0.4.GA\server\default\deploy\ejb3.deployer and C:\jboss-4.0.4.GA\lib directories. The JAR file javaee.jar I took from lib directory of Sun Java System Application Server Platform Edition 9. After copying javaee.jar to these locations, I am to run all examples of EJB3Trail. There may be side effect due to javaee.jar but I could not see any error during EJB3Trail testing. ------------------------ Shahabuddin Khan View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3966382#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...