How to specify SSL protocol to use for WebClient class

From the suggested other questions, I was able to solve it by adding the following line to my code:

System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;

This disabled TLS 1.0 from the client, and then the server accepted the connection.

Hope this helps someone else with the same issue. Although the answer is similar to those other questions, it wasn't obvious from the questions asked that this was the case, so I don't feel that this is a duplicate.

I have found a slightly more strict version of switching on and off TLS versions in c#.

This can be used with .Net 4.5 and above.

// Remove insecure protocols (SSL3, TLS 1.0, TLS 1.1)
ServicePointManager.SecurityProtocol &= ~SecurityProtocolType.Ssl3;
ServicePointManager.SecurityProtocol &= ~SecurityProtocolType.Tls;
ServicePointManager.SecurityProtocol &= ~SecurityProtocolType.Tls11;
// Add TLS 1.2
ServicePointManager.SecurityProtocol |= SecurityProtocolType.Tls12;

This makes sure that even if the server is able to use 1.0 or 1.1 we can specifically exclude this from occurring.