Hi Michele

I think you've hit the issue "site cannot be reached" previously.  Can you RDP to the site?  Can you directly access the server and access CRM?  Can you try different access addresses, e,g. IP address and FQDN?  

If there is an issue with the DNS settings or the DNS server, the browser may not be able to connect to the website. In this case, you can try clearing your browser's cache and cookies or changing your DNS server. Sometimes, firewall or antivirus software can block access to certain websites. You can try disabling these programs temporarily to see if that resolves the issue. The website's domain name may have expired or been taken down. The website's server may be overloaded or experiencing high traffic, which is preventing it from serving your request.

And lastly your browser may have cached issue with the website.

And the SSSessionExpiresInHrs will be a Self Service reference and I think is a red herring in this case.

Have you checked HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\eWare\SelfService

There should be a string value of "SSSessionExpiresInHrs"

Try creating one if not, no value needed