title: How to fix a Joomla plugin manifest?
body: <p>I've developed a simple plugin for Joomla! 3.6 but I can't get it installed on my server. I tried different setup methods and after some researchs I think that the problem resides inside my XML manifest.</p>
  
  <p>The error I get is:</p>
  
  <pre><code>Attention: JInstaller: :Install: Cannot find Joomla XML setup file
  Error: Cannot find installation package
  </code></pre>
  
  <p>My XML manifest is the following:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;extension version="3.6" type="plugin" group="mygroup" method="upgrade"&gt;
  &lt;name&gt;plg_mygroup_emailnotify&lt;/name&gt;
  &lt;author&gt;Frollo&lt;/author&gt;
  &lt;creationDate&gt;2017-01-25&lt;/creationDate&gt;
  &lt;copyright&gt;Copyright (C) 2017 Frollo&lt;/copyright&gt;
  &lt;license&gt;GNU General Public License version 2 or later; see LICENSE.txt&lt;/license&gt;
  &lt;authorEmail&gt;&lt;/authorEmail&gt;
  &lt;authorUrl&gt;&lt;/authorUrl&gt;
  &lt;version&gt;1.0.1&lt;/version&gt;
  &lt;description&gt;PLG_MYGROUP_EMAILNOTIFY_XML_DESCRIPTION&lt;/description&gt;
  
  &lt;files&gt;
      &lt;filename plugin="emailnotify"&gt;emailnotify.php&lt;/filename&gt;
      &lt;folder&gt;language&lt;/folder&gt;
  &lt;/files&gt;
  
  &lt;config&gt;
      &lt;fields name="params"&gt;
  
          &lt;fieldset name="PLG_FIELDSET_GENERAL"&gt;
            &lt;field name="general_mailfrom_address"
                   type="email"
                   label="PLG_GENERAL_MAILFROM_ADDRESS"
                   description="PLG_GENERAL_MAILFROM_ADDRESS_DESC"
              /&gt;
  
              &lt;field name="general_mailfrom_name"
                     type="text"
                     default=""
                     label="PLG_GENERAL_MAILFROM_NAME"
                     description="PLG_GENERAL_MAILFROM_NAME_DESC"
                     size="30" /&gt;
  
          &lt;/fieldset&gt;
          &lt;fieldset name="PLG_EMAILNOTIFY_FIELDSET_ESTIMATE"&gt;
            &lt;field
              name="estimate_approve_link"
              type="text"
              default="http://wwww.example.com"
              /&gt;
          &lt;/fieldset&gt;
  
      &lt;/fields&gt;
  &lt;/config&gt;
  &lt;/extension&gt;
  </code></pre>
  
  <p>EDIT - Some other details:
  I have had no troubles installing other plugins or components on the server. The directory structure is the following:</p>
  
  <pre><code>+ emailnotify
    + language
      + it-IT
        - it-IT.ini
    - emailnotify.php
    - emailnotify.xml
  </code></pre>