JMeter Error in NonGUIDriver java.lang.NullPointerException
<p>I am trying to run a JMeter test on my server using command line. I am connecting with ssh into a rabbitMQ server from my windows machine and I'm running the jmeter on the rabbitmq server, I have the jmx file I want to run but when I run a command like "jmeter -n -t server.jmx" I get an error like this "Error in NonGUIDriver java.lang.NullPointerException"</p>

<p>I have been through many questions and answers but none of them solved my problem. I have included jar files into the lib/ext folder. I have checked my jmeter versions comparing my windows machine with the Linux server, search-and-replace the HTTPSamplerProxy with HTTPSampler in the .jmx test file etc. etc.</p>

<p>This is the "jmeter.log" file I have:</p>

<pre><code>2016/02/05 07:12:37 INFO  - jmeter.save.SaveService: All converter versions present and correct
2016/02/05 07:12:37 ERROR - jmeter.save.SaveService: Conversion error com.thoughtworks.xstream.converters.ConversionException: com/rabbitmq/client/ShutdownSignalException : com/rabbitmq/client/ShutdownSignalException
---- Debugging information ----
message             : com/rabbitmq/client/ShutdownSignalException
cause-exception     : java.lang.NoClassDefFoundError
cause-message       : com/rabbitmq/client/ShutdownSignalException
first-jmeter-class  : org.apache.jmeter.save.converters.TestElementConverter.unmarshal(TestElementConverter.java:100)
class               : org.apache.jmeter.save.ScriptWrapper
required-type       : com.zeroclue.jmeter.protocol.amqp.AMQPConsumer
converter-type      : org.apache.jmeter.save.ScriptWrapperConverter
path                : /jmeterTestPlan/hashTree/hashTree/hashTree/com.zeroclue.jmeter.protocol.amqp.AMQPConsumer
line number         : 29
version             : 2.8.20130705
-------------------------------
2016/02/05 07:12:37 ERROR - jmeter.JMeter: Error in NonGUIDriver java.lang.NullPointerException
        at org.apache.jmeter.gui.tree.JMeterTreeModel.addSubTree(JMeterTreeModel.java:93)
        at org.apache.jmeter.JMeter.runNonGui(JMeter.java:745)
        at org.apache.jmeter.JMeter.startNonGui(JMeter.java:723)
        at org.apache.jmeter.JMeter.start(JMeter.java:388)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.apache.jmeter.NewDriver.main(NewDriver.java:216)
</code></pre>

<p>Thanks,</p>