I found that I had moved jbpm-jpdl.jar into the server lib dir and also had it in my service archive. The jbpm code tries to load the handler class using the same loader that loaded the jbpm lib, which was the root loader, not my services loader which was a descendant of that one. When it did not find it it tried to get it from the database. When I removed the jar from the server lib directory then it found my code because the same class loader loaded jbpm that loaded mine. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4145598#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...