Hi I encountered the exception below running JBoss 4.0.3SP1 on JDK6. The exception was thrown in an application that hadn't been throwing that exception on JDK1.4. Interesting: The first occurrence of the exception takes place after a seemingly random amount of time after launch (0 - 60 min). Once it has been thrown, it won't stop being thrown. Has anyone experienced similar things? 10:10:00,187 SEVERE [EJobEngine] Error sending JMS message; job is NOT run javax.jms.JMSSecurityException: User: null is NOT authenticated at org.jboss.mq.security.SecurityManager.authenticate(SecurityManager.java:215) at org.jboss.mq.security.ServerSecurityInterceptor.authenticate(ServerSecurityInterceptor.java:51) at org.jboss.mq.server.TracingInterceptor.authenticate(TracingInterceptor.java:734) at org.jboss.mq.server.JMSServerInvoker.authenticate(JMSServerInvoker.java:287) at org.jboss.mq.il.uil2.ServerSocketManagerHandler.handleMsg(ServerSocketManagerHandler.java:204) at org.jboss.mq.il.uil2.SocketManager$ReadTask.handleMsg(SocketManagerjava:369) at org.jboss.mq.il.uil2.msgs.BaseMsg.run(BaseMsg.java:377) at EDU.oswego.cs.dl.util.concurrent.PooledExecutor$Worker.run(PooledExecutor.java:743) at java.lang.Thread.run(Thread.java:619) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4040852#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...