When placing more than 1 product in the shopping cart, customers receive an error message saying 'order can't be shipped to this address' and as a result they cannot proceed to shipping method & payment.
- The problem does not occur with only 1 product in the shopping cart (identical address of course).
- The problem is not country-specific, so same issue regardless of shipping country.
- The problem is not product-specific, same problem with different products.
- The problem must have occured after last Saturday (28 Jan.), because that's when we last had an order for more than 1 product.