The request was aborted: Could not create SSL/TLS secure channel

Question

We are unable to connect to an HTTPS server using WebRequest because of this error message:

The request was aborted: Could not create SSL/TLS secur

Answer 1

After many long hours with this same issue I found that the ASP.NET account the client service was running under didn't have access to the certificate. I fixed it by going into the IIS Application Pool that the web app runs under, going into Advanced Settings, and changing the Identity to the LocalSystem account from NetworkService.

A better solution is to get the certificate working with the default NetworkService account but this works for quick functional testing.