Clicking my purchase button displays the message "Invalid Processor"
This error happens if you are using a Buy Now purchase button/link for a checkout method you currently do not have set up in your E-junkie Dashboard under Manage Seller Account > Edit Profile.
When you obtain your Buy Now button/link code, before you copy that code, you would first select the checkout method it will use—e.g., PayPal or Credit Card. Normally, you can only select from the checkout method(s) currently set up in your E-junkie Profile settings; however, if you later remove a checkout method from your E-junkie Profile, clicking any Buy Now buttons/links you'd previously obtained for that method will then show the "Invalid Processor" error.
E.g., if you enable a card payment gateway in your Profile settings and obtain a Buy Now button for Credit Card checkout, but then later disable that card payment gateway in your Profile, that Buy Now button for card payment would start showing the "Invalid Processor" error.
If you are using PayPal, go to Manage Seller Account > Edit Profile and enter your PayPal Email in the space indicated, then click Submit to apply changes. Note that must be the email address you use to log into PayPal, or you can use a secondary email you have added to your PayPal account and Confirmed with PayPal. If you enter a PayPal Email that isn't either of those, it will be removed the first time a buyer tries sending a checkout payment to it.
For direct card payment, see the Payment Gateways section here listing the card processors we support; each of those are linked to our setup instructions for that service. Buy Now button/link codes you obtain with the Credit Card checkout method selected will always use whichever card Payment Gateway you currently have set up in your E-junkie Profile, so this will automatically pick up the change if you switch to a different card Payment Gateway later.
If you want to offer buyers a choice of any checkout method you currently accept, you can use Add to Cart buttons/links rather than Buy Now. In this case, our shopping cart will show buyers a separate checkout button for each checkout method currently enabled in your E-junkie Profile, and this will automatically pick up any changes you may make there.