Problem #

You see the following error while using a PayPal® payment gateway module:

L_SHORTMESSAGE0 => Security error

Cause #

Your API credentials are invalid in the payment gateway configuration at Configuration () > System Settings > Payment Gateways.

Solution #

Ensure that your API credentials at Configuration () > System Settings > Payment Gateways match the credentials in your PayPal account.

Last modified: January 30, 2025