Error when editing an order

Hi,



I have the latest version 2.22, but get the following error when I edit an order :



Warning: Invalid argument supplied for foreach() in /var/www/vhosts/capitalcaterers.co.uk/httpdocs/core/fn.cart.php on line 4755



Any changes I make whilst going through the edit order process are not saved. I have made a few modifications to my site, but can’t imagine that it would have caused this problem. Does anyone have any ideas why this is happening?



Mike