C# HttpClient An existing connection was forcibly closed by the remote host

Question

I\'m working on an integration with Alternative Payments using their hosted page integration. Their C# SDK does not have this integration available at the moment, but as you

Answer 1

This worked for me, the first line ensures the protocols ssl3 and TLS1.2, and the second line ignores any potential certificate errors (ignore and continue - like expired certs.):

ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls12;
ServicePointManager.ServerCertificateValidationCallback +=  (sender, certificate, chain, sslPolicyErrors) => true;