right click on a the folder > file attributes... You need to set permission to read+write+execute for owner and the group. If it is not working set the public permission to read+write+execute.
I am not sure Vanilla can run on free.fr out of box, you might have to set the path to a session folder. You have to look for help from other users of free.fr for this problem.
Yes, but when i do "file attributes" and that I modify the CHMOD, and that I go again to the file attributes, it comes back to the previous CHMODs (700 and 644).