I wrote an email to Tom: anonymous wrote : Tonight I tested with JBoss AS 4.0.4GA Patch 1 (from the JEMS | | installer - jems-installer-1.2.0.BETA). ...I got the exception listed below ... He replied: anonymous wrote : there are 2 libs: jboss-backport-concurrent.jar and jbossretro-rt.jar | | Those libs are part of jboss 4.0.4.GA. I don't know if they are part of your JBoss installation. If not, they should be added. In the distro, i will provide a script that takes the original war and adds these (+other libraries) and prepares it for usage in tomcat standalone. That script can be found in jpdl/dist/src/resources/runtime/deploy in the sources. In doing a little more digging it appears that jboss-backport-concurrent.jar and jbossretro-rt.jar are removed from JBoss AS 4.0.4GA Patch1 EJB3 Profile as part of creating the EJB Profile. See http://wiki.jboss.org/wiki/Wiki.jsp?page=EJB3in404GA View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3986184#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...