All questions related to Legacy API errors go in here, we have a nice handy list below for users to review, if you have questions please raise them here.
Common Response Codes:
Generic response code when the customer's credit card failed authorization. Instruct the customer that to usealternative payment method or they can contact PayPal Customer Service for assistance
Internal Error. Attempt a 3-5 retries, if the attempt continues to fail after 2 hours please contact MTS for support
Authentication failed. API credentials are incorrect, or the API call is sent to the wrong endpoint (sandbox Vs Live)
Processor decline on Pro. This occurs when the customers card is declined by the card issuing bank, not PayPal.
Funding Source Decline. However redirecting customer back to PayPal using the same EC token will allow them select or add a new funding source.
Gateway Decline on Pro, it means PayPal declined the payment for various reasons, e.g. AVS failed, high risk, CVV2 mismatch.
The transaction was refused because the AVS response returned the value of N, and the merchant account is not able to accept such transactions, customer needs to confirm that the address entered matches the address associated with the card at issuer.