It appears you have removed the PayPal Email setting for your account, so our system can't tell what PayPal account you want to use to receive checkout payments. Go to your Seller Admin > Edit Profile screen, enter your PayPal Email address, and click Submit to save changes.
I notice you recently emailed us about testing an affiliate program; note that settings in your Affiliate Admin > Edit Profile screen are the same as those in your Seller Admin > Edit Profile -- i.e., you don't have a separate "affiliate account" and "seller account", they're just different Admin screens to manage different functions of one and the same account.
