Hi Bernd, Redeployment does not seem to work at the moment. Somehow the class loader gets messed up and reflection access starts to fail. I tested these examples using JDK 1.4.2/1.5.0 and JWSDP 1.6 only. Perhaps either JDK 1.6.0 or JWSDP 2.0 are the reason for the NPE in your first post. Please switch to JDK 1.5.0 and/or JWSDP 1.6. Note that you should not have to copy any libraries from the app server, nor use the endorsement mechanism. The tools and Ant scripts provided with the product should be able to set the correct classpath automatically. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4122587#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...