Re: My installation does not launch …
This does not appear to be correct:
$bb->wp_siteurl = 'http://www.subventions.fr/wordpress';
Your wordpress site comes up at
http://www.subventions.fr/ so the wordpress part is superfluous. I think you’ve got a path problem somewhere. Normally you install bbPress like this:
maps to http://www.subventions.fr/
maps to http://www.subventions.fr/forum/
forum is a subdirectory of wordpress in a typical integrated setup. Is that your setup? If so, then your config is wrong.