C# HttpWebRequest The underlying connection was closed: An unexpected error occurred on a send
In 4.0 version of the .Net framework the ServicePointManager.SecurityProtocol only offered two options to set: Ssl3: Secure Socket Layer (SSL) 3.0 security protocol. Tls: Transport Layer Security (TLS) 1.0 security protocol In the next release of the framework the SecurityProtocolType enumerator got extended with the newer Tls protocols, so if your application can use th …