@george1421
Hi George,
Thanks for your reply.
I had no infos in the apache logs, so i think you right there was a redirection.
So, i just uninstalled manually fog (mv /var/www/fog to fog.bak & /opt/fog to opt.bak), uninstall mysql with apt-get purge mysql-* and reinstall completly fog from the git dir.
Now it works.
Arnaud