Found the problem, although I was not expecting that the method executeAction in org.jbpm.graph.def.GraphElement would also print the exception cause. Should this happen by the way? The problem is that somehow the field detailedMessage in exception object is not being filled, and when doing myException.getMessge() the return value is null. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4001855#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...