I was able to reproduce this by first creating a message on a queue using the web console.
I then used Qpid Proton messenger to consume via the amqp protocol from that queue. When the consumer connects, I get the exception in my amq log. So I think the issue is consuming a message with AMQP that doesn't have the JMS_AMQP_MESSAGE_FORMAT property set. -- View this message in context: http://activemq.2283324.n4.nabble.com/java-lang-NumberFormatException-property-JMS-AMQP-MESSAGE-FORMAT-was-null-tp4672352p4676346.html Sent from the ActiveMQ - User mailing list archive at Nabble.com.
