title: RabbitMQ: Unable to start rabbitmq_management plugin
body: <p>Version:</p>
  
  <pre><code>&gt; sudo rabbitmqctl status | grep '{rabbit,"RabbitMQ",'
        {rabbit,"RabbitMQ","3.5.6"},
  </code></pre>
  
  <p>Error:</p>
  
  <pre><code>&gt; sudo rabbitmq-plugins enable rabbitmq_management
  
  Plugin configuration unchanged.
  
  Applying plugin configuration to rabbit@ip-172-31-26-169... failed.
   * Could not contact node rabbit@ip-172-31-26-169.
     Changes will take effect at broker restart.
   * Options: --online  - fail if broker cannot be contacted.
              --offline - do not try to contact broker.
  </code></pre>
  
  <p>Rabbit is running:</p>
  
  <pre><code>&gt; sudo service rabbitmq-server status
  Status of node 'rabbit@ip-172-31-26-169' ...
  [{pid,22865},
  ..
  </code></pre>