I am getting the following problems. I am using only PayPal Express Checkout but the card fields still show on the form (even though accept only is set to paypal).
I have no CSS, but that is because I tried adding the folder and file wp-content/mu-plugins/s2-o.php
That didn't work so I removed it now I have no CSS on my pro form. The only error I get is the one shown in the screenshot.