I have this problem when I click on "Proceed to checkout" in the cart and try to check out using a credit card, I get the "This transaction cannot be processed.." error underneath the "Process Order" button. It only says, "This transaction cannot be processed.." nothing else. I am able to checkout when I use Paypal. This site is hosted on IIS on my computer and is not live (Is Live is not checked in the payment settings). I'm using Paypal sandbox. I also used the credit card numbers that dashCommerce provided to test the cart. Is this error because I'm not live? Or is it something with the code?