Thanks for your response. I searched the forums prior to sending in my message, but didn't find the articles you pointed me to. I think I'm making progress, but am still coming up short. My applications are external to JBoss. I'm able to send/receive messages without any problem. However, my sender app wants to monitor the number of messages in the queue via JMX. From the links you pointed me to, I think my problem was mostly descriptor related. I now have: <mbean code="org.jboss.jms.server.destination.QueueService" | name="jboss.messaging.destination:service=Queue,name=MyQueue" | xmbean-dd="xmdesc/Queue-xmbean.xml"> | <depends optional-attribute-name="ServerPeer">jboss.messaging:service=ServerPeer</depends> | <depends>jboss.message:service=PostOffice</depends> | ...snip security part guest read write | </mbean> | | <mbean code="org.jboss.invocation.jrmp.server.JRMPProxyFactory" | name="jboss.jmx:type=adaptor,name=MyQueueTarget,protocol=jrmp,service=proxyFactory"> | <depends optional-attribute-name="InvokerName">jboss:service=invoker,type=jrmp</depends> | <depends optional-attribute-name="TargetName"> | jboss.messaging.destination:service=Queue,name=MyQueue | </depends> | <attribute name="JndiName">MyQueueMBean</attribute> | <attribute name="InvokeTargetMethod">true</attribute> | <attribute name="ExportedInterfaces">org.jboss.jms.server.destination.QueueMBean</attribute> | <attribute name="ClientInterceptors"> | <interceptors> | <interceptor>org.jboss.proxy.ClientMethodInterceptor</interceptor> | <interceptor>org.jboss.proxy.SecurityInterceptor</interceptor> | <interceptor>org.jboss.jmx.connector.invoker.client.InvokerAdaptorClientInterceptor</interceptor> | <interceptor>org.jboss.invocation.InvokerInterceptor</interceptor> | </interceptors> | </attribute> | </mbean> | Inside my code, Its really simple: | mBeanServer = (MBeanServerConnection) ctx.lookup("jmx/rmi/RMIAdaptor"); | org.jboss.jms.serer.destination.QueueMBean qmbean = (org.jboss.jms.server.destination.QueueMBean) ctx.lookup("MyQueueMBean"); System.out.println(qmbean) --> JRMPInvokerProxy When I attempt to do a qmbean.getMessageCount() I get an IllegalStateException: Failed to find method for hash:..... and it then prints the methods available on a QueueMBean. I *have* searched the forum and this error seems to imply a jar related problem. I have ensured that my version of jboss-messaging-client.jar is one provided in messaging 1.2.0sp1. I have looked at the dates on the QueueMBean class within that jar, and they match the dates/size of the QueueMBean located in the jboss/server/messaging/deploy/jboss-messaging.sar/jboss-messaging.jar. One post I read at http://www.jboss.com/index.html?module=bb&op=viewtopic&t=92737 says that there was a problem with old JMX classes bundled in the jboss-messaging-client.jar. I removed those and it still doesn't work. The jboss-messaging-client.jar is the first jar in my classpath. At this point, I'm not sure where the incompatibility is. Any ideas? Thanks. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4048486#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...