Finally I attached a debugger to the broker, know I am getting a little bit more information about the problem. Here is what I am getting as WARN :
11:19:16,308 WARN [org.apache.activemq.transport.mqtt.MQTTProtocolConverter] (ActiveMQ Transport: tcp:///192.168.0.116:59362@1884) Exception occurred processing: MQTTFrame { type: CONNACK, qos: AT_MOST_ONCE, dup:false }: org.apache.activemq.transport.mqtt.MQTTProtocolException: Unknown MQTTFrame type: 2 Do you have an idea why I am getting this problem ? -- View this message in context: http://activemq.2283324.n4.nabble.com/WARN-org-apache-activemq-broker-TransportConnection-Transport-qtp906254668-147-Transport-Connection-g-tp4725962p4726032.html Sent from the ActiveMQ - User mailing list archive at Nabble.com.