Add to cart not working on vm 2.08a

[matrix_jo]

Hello , suddenly on this eshop , www.gsmshop.gr cart stop working. I add a product in the cart , cart say it is empty , the checkout not working and orders cannot be completed , can anyone help me? Also I receive this error : mdebug self::$_jpConfig->lang el_gr
vmdebug vmTime: loadConfig db no: 0. 00553393363953