The client and server cannot communicate, because they do not possess a common algorithm – ASP.NET C# IIS TLS 1.0 / 1.1 / 1.2 – Win32Exception
There are several other posts about this now and they all point to enabling TLS 1.2. Anything less is unsafe. You can do this in .NET 3.5 with a patch.You can do this in .NET 4.0 and 4.5 with a single line of code In .NET 4.6, it automatically uses TLS 1.2. See here for … Read more