Why is checkout not working on my sub-sites with Marketpress?

I have marketpress installed with Wordpress 3.5.1. I can check out fine on the main site http://www.mdbetter.com but not on either sub site - soap.webonmission.com or http://www.betterfam.com. I get a whoops error when using manual checkout and no error but not processed order when using paypal express. Is there is a setting that I have missed somewhere?