GeocortexIdentityServer Security

I am attempting to configure security on my site in GE 4.0.2 and SL 2.1 using the Geocortex Identity Server. I edited it using the information I found when I ran the GeocortexIdentityServer.Setup.exe but it still fails with the message:

"URL is invalid. Unable to connect to the remote server"

I'm not quite sure what I'm doing wrong. Any suggestions?

Stephanie