anonymous wrote : What is rcp pluging? see http://wiki.eclipse.org/index.php/Rich_Client_Platform. Meanwhile we found the reason for the ClassNotFoundError(s). When packaging jboss inside an rcp-plugin, then the root classloader isn't the jboss one anymore, instead it is the bundle-Classloader of the eclipse equinox/osgi platform. So we had to make the relevant jboss jar's known to the equinox platform via their MANIFEST.MF. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4225632#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...