Sometimes users may experience problem when emptying the Shopping Cart. Commonly users get 'invalid item reference key #### for promo code' error message.
There are two possible ways to resolve this problem:
1. Place 0 in the quantity field of the affected items in the Shopping Cart.
2. If the above fails, another viable solution is to login to the Web Store and use the following the URL:
www.mysite.com/app/site/backend/emptycart.nl ['www.mysite.com' is the domain of the website]
Just copy the above URL in the address bar of the browser and hit enter. This will empty the current contents of the cart.