Hi, I have the same error. In my case, it is the Borlabs Cookies plugin that seems to be causing the problem. Once I disable it, the PayPal buttons load and the error is gone.
Turned on, the PayPal buttons are not rendered (the PayPal div wrapper is empty) the default “Buy Now” button is what causes the error when clicked.
Any idea how to stop borlabs cookies from affecting in the checkout page?
Cheers