Hi Peter, you are right. It were the wrong sources. I downloaded one more time and now the build is successful and I can start the application server. Thank you very much! If you come to Germany I will spent a beer. Just for info: I newly installed jdk1.5.0_08 and JBoss 5.0.0.Beta1 (binary package) on Windows. In this environment I also get Exceptions. Best regards, Frank View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3997354#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...