Error downloading a plugin

Question

I have created my own repository for QGIS. If I now install my plugin from this repository, I get the following error message:

Plugin has disappeared: The plugin seems to have been installed but I don't know where. Probably the plugin package contained a wrong named directory. Please search the list of installed plugins. I'm nearly sure you'll find the plugin there, but I just can't determine which of them it is. It also means that I won't be able to determine if this plugin is installed and inform you about available updates. However the plugin may work. Please contact the plugin author and submit this issue.

When I restart QGIS and activate the plugin, it works without problems.

My repository looks like this:

<?xml version="1.0"?>
<plugins>
    <pyqgis_plugin name="Name" version="0.1">
        <description>xxx</description>
        <homepage>www.xxx.com</homepage>
        <qgis_minimum_version>3.0</qgis_minimum_version>
        <file_name>plugin.zip</file_name>
        <author_name>Name</author_name>
        <download_url>http://xxx.com/plugin.zip</download_url>
    </pyqgis_plugin>
</plugins> 

Answer 1

I have realised that naming the file plugin.zip or plugin-x.y.z.zip is failing while plugin.x.y.z.zip actually works.

If this is of any help, here is a Python package which helps at deploying QGIS plugins, either on the official or as custom repository on Github: https://github.com/opengisch/qgis-plugin-ci