Petals SE Activiti

2015/05/26 14:36:24,555 GMT+0200 WARNING [org.activiti.engine.delegate.event.impl.ActivitiEventSupport] : Exception while executing event-listener, which was ignored
java.lang.NullPointerException
	at org.ow2.petals.activitibpmn.event.ProcessInstanceCompletedEventListener.createLogData(ProcessInstanceCompletedEventListener.java:55)
	at org.ow2.petals.activitibpmn.event.AbstractMonitLoggerEventListener.processEvent(AbstractMonitLoggerEventListener.java:47)
	at org.ow2.petals.activitibpmn.event.AbstractEventListener.onEvent(AbstractEventListener.java:56)
	at org.activiti.engine.delegate.event.impl.ActivitiEventSupport.dispatchEvent(ActivitiEventSupport.java:105)
	at org.activiti.engine.delegate.event.impl.ActivitiEventSupport.dispatchEvent(ActivitiEventSupport.java:98)
	at org.activiti.engine.delegate.event.impl.ActivitiEventDispatcherImpl.dispatchEvent(ActivitiEventDispatcherImpl.java:65)
	at org.activiti.engine.impl.pvm.runtime.AtomicOperationActivityEnd.eventNotificationsCompleted(AtomicOperationActivityEnd.java:74)
        ...