You might get error
Plugin Install: No plugin file specified
if you develop your own Joomla plugin. I managed to get such error when I finished module for Joomla but decided it is better to be implemented as content plugin and start to make conversion.
To fix it you must make sure you have group=”content” or whatever type your plugin is in your XML file extension/install part
<install type="plugin" version="1.6" group="content">