EPub and HTML export doesn't seem to work

I am a PhD student and a new user to fidus writer. I plan to use it from the web platform to write collaborative article with my colleagues. I also wanted to use the possibility offered by a semantic writter to export as HTML files my articles so that I could directly post them on my personnal web page (via html format). However, exporting in HTML and EPub doesn’t seem to work for me. When I try, I got an alert saying the test export has been launched, but then nothing happen, no download possibilities. All the other formats do work on the contrary, and quickly open a download window.
Remark : I currently have no paid subscription, just using the free online version.
Thanks for any help or information on this topic !

Hey, I will be in touch via email. In general the feature is working. There may be something specific to your content that breaks it.