JON agent fails to connect to server and server reports "InstanceNotFoundException: jboss.remoting:service=invoker,transport=servlet is not registered"

Issue

• The sender object is currently not sending commands now
• The agents will not start and log the following messages:

        WARN  [main] (org.rhq.enterprise.agent.AgentMain)- {AgentMain.plugin-update-failure}Failed to update the plugins.. Cause: java.lang.IllegalStateException: The sender object is currently not sending commands now. Command not sent: [Command: type=[remotepojo]; cmd-in-response=[false]; config=[{rhq.send-throttle=true}]; params=[{invocation=NameBasedInvocation[getLatestPlugins], targetInterfaceName=org.rhq.core.clientapi.server.core.CoreServerService}]]

• When attempting to ping the server, the following message appears:

        Pinging...
        Failed to execute prompt command [ping]. Cause: java.lang.IllegalStateException:
        The sender object is currently not sending commands now. Command not sent: [Comm
        and: type=[remotepojo]; cmd-in-response=[false]; config=[{rhq.send-throttle=true
        }]; params=[{invocation=NameBasedInvocation[ping], targetInterfaceName=org.rhq.e
        nterprise.communications.Ping}]]

• Agent to server communication fails with the following error:

        ERROR [org.apache.catalina.core.ContainerBase] Servlet.service() for servlet ServerInvokerServlet threw exception
java.lang.reflect.UndeclaredThrowableException
    at $Proxy534.processRequest(Unknown Source)
    at org.jboss.remoting.transport.servlet.web.ServerInvokerServlet.processRequest(ServerInvokerServlet.java:128)
    at org.jboss.remoting.transport.servlet.web.ServerInvokerServlet.doPost(ServerInvokerServlet.java:157)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.rhq.helpers.rtfilter.filter.RtFilter.doFilter(RtFilter.java:125)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:173)
    at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:182)
    at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
    at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:157)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:241)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
    at java.lang.Thread.run(Thread.java:662)
Caused by: javax.management.InstanceNotFoundException: jboss.remoting:service=invoker,transport=servlet is not registered.
    at org.jboss.mx.server.registry.BasicMBeanRegistry.get(BasicMBeanRegistry.java:523)
    at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:653)
    at javax.management.MBeanServerInvocationHandler.invoke(MBeanServerInvocationHandler.java:288)