I am using Sagepay InFrame Server integration. and I am using windows authentication and when I am calling the Sagepay from my portal page (on click of the payment button),I am getting below error. and When I tried with the Forms Authentication, it is working fine. Could you please help me to sort out this issue?
Thanks.
This is occurring because Sage Pay cannot reach your NotificationURL. You should make sure that your NotificationURL is externally visible on the internet, without authentication.