IPN was not sent, and the handshake was not verified. Please review your information.
The handshake error is most likely to occur when your server/keystore config is non-compliant with the upgraded PayPal SSL encryption algorithms. IPN simulator will connect againest the PayPal Sandbox environment, which has been upgraded with Versign G5 root cert / SHA-2 encryption algorithms (btw this is an industry standard as supposed to be everywhere in … Read more