Exception on orderValidation

[ada]

Hi, 

i have 3 stores , but only 1 is giving me an exception after payment.

the exception :  RecursiveDirectoryIterator::__construct(/var/www/accountname/data/www/sitename/cache/smarty/cache/blockbestsellers/): failed to open dir: Permission denied

in defines.ini cache is point to : define('_PS_CACHE_DIR_',            _PS_ROOT_DIR_.'/cache/');  -an internal path of the shop, but for some reason the constructor above tries to write to /var/www/....

i do have var folder in my tree but i can't create new folders in it  , does anyone knows where does it takes that path from ?

disabling that module didn't help, it fails on the same exception on a different module

 

Thank you !