PCI error "This transaction cannot be processed. The merchant's account is not able to process transactions."

This message was displayed when I tested the PayPal widget in a form. Why is the payments widget not working and what needs to be done to correct the problem? See the attached image.

The error usually occurs when the PayPal account is not a business or Pro PayPal account.  PayPal Pro integration can only be used with a PayPal Pro or PayPal Business account.  If you do not have either of those, using a regular PayPal field in the form should allow for processing transactions.