The application is using jBPM under WebSphere 6.1 and using jbpm-enterprise.jar that ships with JBPM 3.2.2 for asynchronous continuation. When JBPM hits an async node, the JmsMessageServiceImpl class gets invoked to send a JMS message, resulting in this exception:

Note: the WebSphere MQ messaging provider is being used.

java.lang.UnsupportedOperationException: MQJMS1014: operation invalid for identified producer
at com.ibm.mq.jms.MQMessageProducer.send(MQMessageProducer.java:1184)
at com.ibm.mq.jms.MQMessageProducer.send(MQMessageProducer.java:3132)
at com.ibm.ejs.jms.JMSMessageProducerHandle.send(JMSMessageProducerHandle.java :1014)
at org.jbpm.msg.jms.JmsMessageServiceImpl.send(JmsMessageServiceImpl.java:77)
at org.jbpm.graph.def.Node.enter(Node.java:316)
[...]

Looking up the error code at the top of the stack trace yields:

MQJMS1014 Operation invalid for identified producer.

Explanation: The QueueSender.send method has been performed on an identified QueueSender, which contradicts the JMS specification
User Response: See QueueSender and the JMS specification (http://java.sun.com/products/jms/docs.html) for further information.