MarketPress Issue - No Payment options showing up on Payment page

When I get to the payment page I have no payment options. I only have one selected and setup which is the Paypal Express. I have entered all the required information on the settings page. If I click continue on that payment page I get the following error -

There was a problem connecting to PayPal to setup your purchase. Please try again.

* 10002 - Security error - Security header is not valid