Customers cannot add products to their shopping carts

Your customers may find their shopping carts empty when trying to add some products to it to proceed to the checkout. This issue is quite often caused by incorrect handling of PHP session files on the server. The following parameters need to be checked to rectify that:

1. PHP configuration should contain the path to the server directory where PHP session files are supposed to be stored; it shall be specified in parameter session.save_path.
2. Access rights to the directory where session files should be stored must allow the web server to modify its contents by saving session files in it.