Website hosted on IIS keeps asking for authentication even though only Anonymous Authentication is enabled

Solution 1:

I investigated the issue and it seemed to be tied to an application called Windows Admin Center, which I promptly uninstalled (use discretion). I then restarted the World Wide Web Publishing Service service. Then I found this answer on StackExchange:

Later I uninstalled it and it's the same error. I can't find how to release 443 port.

Per Microsoft, if you previously had Windows Admin Center installed, and now nothing else can use the same TCP/IP port, try running:

netsh http delete sslcert ipport=0.0.0.0:443
netsh http delete urlacl url=https://+:443/

I thought that solved my issue, but I received a generic "This webpage cannot be found", even though the http counterpart worked as normal. To fix the issue, click on the Default Web Site on the left pane in IIS (first expand Sites), then click on Bindings... in the right pane, then click on the https entry you added and make sure your certificate is still selected when you click Edit.... Mine was deselected in the drop-down and the generic Not Selected was the value. Select your certificate again, click Ok, and it worked immediately for me.