Then something is wrong. As soon as the plugin in enabled at the course level I am uncapable to either preview or download the course. See below the two messages I get for each function.

If I disable the plugin I can preview and download just fine. I can also access the course with no problem once uploaded on a web server (see the following link):

http://formenligne.000webhostapp.com/les-approches-mthodes/index.html