What can we do, if Internet pages are not accessible due to TLS issues and the browser only displays error messages because communication via TLS/SSL fails?
Microsoft has addressed this issue for ASP-NET in conjunction with HTTP web calls. As soon as a target URL is called via https, TLS/SSL is used and errors can occur.
(TLS/SSL error, Source: Microsoft)
If the browser cannot verify the SSL certificates of a website accessed via https, it displays a corresponding warning and refuses to display them (see figure above). In two articles, a Microsoft employee shows how to perform a troubleshooting and how to narrow down the cause.