Changing the URL to
https://localhost:5304/ Initially does get me a page saying 'Your connection isn't private' with a link to continue to localhost (unsafe). But clicking that link to go forward loads nothing. In Edge, that states 'This page isn't working right now" with an HTTP ERROR 400 showing. No other option available.
It does not load the content server page. Also, localhost would do nothing for trying to load it using an external IP from somewhere else over the internet. The content server is broken with this latest update.
Normally I have had an SSL certificate being used in the settings, which is why I use HTTPS. For testing, I removed the certificate settings, restarted the content server and tried loading regular HTTP. It still loads nothing.
It worked fine before updating to v7.20. Literally the content server would load normally yesterday. I upgraded this morning (the only change made) and it is now broken.