Unable to install the X-Pack plugin for Elasticsearch
<p>Hi I have installed both Elasticsearch and Kibana on the same server and I am trying to install the X-Pack plugin for the Elasticsearch. I have downloaded the plugin zip file and I tried the following command.</p>

<pre><code>./plugin install file:///root/x-pack-5.1.1.zip
</code></pre>

<p>And I got the following error:</p>

<blockquote>
  <p>Verifying file:/root/x-pack-5.1.1.zip checksums if available ...
  NOTE: Unable to verify checksum for downloaded plugin (unable to find .sha1 or .md5 file to verify)
  ERROR: Could not find plugin descriptor 'plugin-descriptor.properties' in plugin zip
  `</p>
</blockquote>