You are receiving this error because you need to configure your receipt page URL.
- Log into the Merchant Interface at https://account.authorize.net.
- Click Account from the main toolbar.
- Click Response/Receipt URLs under Transaction Format Settings.
- Click Add URL.
- Enter your Response URL.
- Click Submit.
The "Default Relay Response URL” is https://secure.CivicRec.com/hostedPayment/returnWebhookTransaction/2