Ronald referred to the classloader specifics of JBoss. There are a couple of wiki pages in that respect, eg: http://wiki.jboss.org/wiki/Wiki.jsp?page=GetClassNotFoundExceptionOrNoCla... I think the fourth point 'The class is not visible from where it is being loaded' matches your use case pretty much. It would be interesting to know, however, why your *.war with the included jbpm-jpdl.jar doesn't deploy. This is how the jBPM web console application is deployed (if you don't use the *.ear version). Please provide more details of what is failing and the exceptions you get, as well as the versions (AS, jBPM) so that we can help you further. Just a guess, if it is jBPM 3.2.x on AS 4.2.x, this will not work ootb, but you could follow this wiki to get it going: http://wiki.jboss.org/wiki/Wiki.jsp?page=DeployJbpm3.2WebAppUnderJBoss4.2.x View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4133568#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...