I found it out! It was a bad web service building. I looks like when jbpm-bpel acts as a client (invoke situation) it is sensible to service implementation. I found out that my service was missing the soapAction attribute in the binding. The odd thing was that a test client worked out with that. But I regenerated the service after adding the soapAction and the invoke doesn't broke any more. Bye View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4099373#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...