sorry, that email went of prematurely. I am firing an event at a process created     session = JPAKnowledgeService.newStatefulKnowledgeSession(knowledgeBase, null, env);     processInstance = session.startProcess(CLAIM_FLOW, parameterMap); the process is fired, and this is the line which throws the NullPointerException:     process.signalEvent("DocReviewedEvent", null); Here is my logging info:    Doc Reviewed Event id=16    Doc Reviewed Join id=17    Set Complete id=22    End id=3    java.lang.NullPointerException So as you can see the process completed during the event.   at org.drools.persistence.processinstance.JPAProcessInstanceManager.removeProcessInstance(JPAProcessInstanceManager.java:82) which is this line:         ProcessInstanceInfo processInstanceInfo = em.find( ProcessInstanceInfo.class,                                                            processInstance.getId() ); It's actually the EntityManager which is returning null... I wonder why?