Author archive doesn’t work [closed]

These things are fun because there are so many possibilities.
I’ll start my series of answers here and you can accept it once we get it right.

First thing, your site is allowing directory listings — this is bad for security — but at the moment is helping me see what might be causing the problem 🙂

I can see you have the redirection plugin installed.

Could you deactivate that and try hitting your author URL then? That plugin has a nasty little default setting of doing extra work you may not want it to be doing — and it can sometimes cause problems like this.

Example of Directory Listing: http://www.jack35mm.fr/wp-content/plugins/redirection/