I have been searching around and not been able to find much that is particularly in depth about how to configure the classloading for jboss. I have read through this: http://www.jboss.org/community/wiki/ClassLoadingConfiguration and tried configuring my jboss-app.xml accordingly, by pointing the class that is giving me NoSuchMethodError explicitly at the jar I want it loaded from ( e.g. javax.xml.soap.SOAPElement:loader=myearapp.ear and javax.xml.soap.SOAPElement:archive=saaj-api-1.3.jar ). This doesn't appear to work in the jboss-app.xml at EAR level but only in the jboss-web.xml at WAR level ( e.g. javax.xml.soap.SOAPElement:loader=mywarapp.war ) with the libraries in the WEB-INF/lib, and I have a feeling that is because that is the first place searched for classes. I have also read this: http://www.weiqigao.com/articles/jboss/foil18.html and tried using that suggestion in the jboss-app.xml, it did appear to have some affect but not the desired one of looking at the EAR for classes prior to the app server. I have also read the jboss-app DTD from here: http://www.jboss.org/j2ee/dtd/ ( then the jboss-app_4_0.dtd for my version ) which gives me info about the elements allowed with in the jboss-app.xml but gives no extra information on the values that are valid within those elements. If anyone could provide me with more information about jboss classloading or specifically about the values that are appropriate for the jboss-app.xml loader-repository tag it would be very helpful indeed. this is a bit of a classloading nightmare. Cheers. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4231253#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...