@preciousstuff Hi! Sorry for the late answer! Yes, the problem is solved! As Armin says, it's not a theme problem; i called my host provider and told them the problem, and it's a folder's permission (don't know exactly what they did, but the problem disappear immediately! So, you have to call your host provider again and tell them to solver the permission problems of your host!
Cheers and again, sorry for the late answer!