I've found a possible solution for the NPE. I don't think it's a best practice, but at the moment it works. The fix is manually creating an instance of the sub process and then manually creating a token, like in the following snippet. | token.signal(); | ProcessInstance subProcessInstance = token.createSubProcessInstance(subProcessDefinition); | Token subToken = subProcessInstance.getRootToken(); | subToken.signal(); | subToken.signal(); | However, it doesn't feel that good actually. It looks like I'm doing jBPM's job. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4119610#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...