www.cruaoutdoors.comAnd here is the comment from our customer:
"Ah, I've figured out it's only a particular situation. I was only using the product page
http://cruaoutdoors.com/product/thermo-tent-6-deluxe/ to add to my basket, so with a fresh session (cookies cleared) it always fails. I notice there is a cookie "woocommerce_cart_hash" that has a "null" value and it could be causing the adding to the basket to fail.
Using the Add to basket button directly on
http://cruaoutdoors.com/product-category/tents/ does work though, and the above cookie then has a value set. If I then browse back to the product page and try adding to basket then it also now works, presumably because there is now a 'valid' cart."
Any ideas?