I didn't do anything. I just went to test it and see where the failure message occurred and never got one.
Maybe it had something to do with the item in your cart. Sometimes special characters in item names can cause issues. My guess is that it is an issue with a particular item or items that you can't checkout with. If you figure out the item I'll add it to the cart and debug why, just post back here and let me know how to reproduce the issue.