The issue can be avoided by using the default namespace. Note that this workaround may be difficult if the process XML is generated via marshaling from java objects, e.g. using JAXB, or is generated by other tools that do not allow for control over XML namespaces.

Using the following event listener user code: TestEventListener.java package org.example; import org.apache.log4j.Logger; import org.jbpm.api.listener.EventListener; import org.jbpm.api.listener.EventListenerExecution; public class TestEventListener implements EventListener { public static Logger log = Logger.getLogger(TestEventListener.class); public String test; @Override public void notify(EventListenerExecution execution) throws Exception { log.info( "notify: " + test); } } deploy and execute the following process: <ns1:process key= "event-test" name= "event-test" xmlns:ns1 = "http://jbpm.org/4.4/jpdl" > <ns1:start name= "start" > <ns1:transition to= "task1" /> </ns1:start> <ns1:task name= "task1" > <ns1:on event= "start" > <ns1:event-listener class= "org.example.TestEventListener" > <ns1:field name= "test" > <ns1:string value= "test" /> </ns1:field> </ns1:event-listener> </ns1:on> <ns1:transition to= "end" /> </ns1:task> <ns1:end name= "end" /> </ns1:process> The observed log output will be: "notify:null". However, if the process is deployed using the default namespace, like this: <process key= "event-test" name= "event-test" xmlns= "http://jbpm.org/4.4/jpdl" > <start name= "start" > <transition to= "task1" /> </start> <task name= "task1" > <on event= "start" > <event-listener class= "org.example.TestEventListener" > <field name= "test" > <string value= "test" /> </field> </event-listener> </on> <transition to= "end" /> </task> <end name= "end" /> </process> then the event listener works correctly and the observed output is: "notify:test"