Sometimes when a customer tried to make a purchase using our credit card purchase form, they see this message:

"This transaction cannot be processed. Please contact PayPal Customer Service."

We're sorry you're having trouble making a purchase, and you're seeing this error.

We actually use a PayPal service called Website Payments Pro to process payments using our credit card form. So, customers do need to contact PayPal when they see this message. We're sorry we're not clearer about that.

In our experience, PayPal's customer support is very good.

Also, please note that PayPal does not operate in every country. Here is an article from our Help Center on this topic:

http://help.leanpub.com/en/articles/2511856-i-m-in-a-country-where-paypal-doesn-t-operate-how-can-i-get-a-leanpub-book

We're sorry for not having a better answer for you on this issue.