Getting Error "Error loading discovery document: Issuer name is missing"

Hi Team,
We create sample application using Auth0.OidcClient.WPF is working fine. But when same things if we want to do from our desktop application we are getting Error loading discovery document: Issuer name is missing error. We are working on this since long but still did not get any solution. We found in discussion that - Seems that the problems I ran into was caused by some machines were configured to use IPV6 and dns lookup failed but what is the meaning of that? With such machines sample app also should not work. Please provide some guidance to fix this issue.
Thanks in advance.