"We're sorry, but our payment processor returned an error while processing this transaction. Specific error returned: 10501: This transaction cannot be processed due to an invalid merchant configuration."
We get this error message when we try to submit payment info (e.g., the Payment Gateways Testing credit card number). The payment gateway is PayPal Pro.
We've rechecked
Settings > Store Settings
Settings > Payment > Gateways
Settings > Payment > Methods
and everything seems to be in order.
We've checked diag_curl.php: A-OK.
Where else should we be looking?
(I posted this question a couple of days ago in the General Support section, but have received no replies. I apologize for posting the same question here, but, after receiving no response, I thought maybe I didn't place the original query in the most appropriate section.)
Thanks in advance for any help!