Hi ecoron, let's see whether we can figure it out.

First, though, in case you are using an old bookmark that isn't redirecting correcting, does the issue happen on the home page here:

https://www.aol.com/

If you still get an error, look for an "Advanced" button on the error page and copy/paste the contents of that section into a reply here.

Usually there is a code like SEC_ERROR_PROBLEM that you can look up in this article: How to troubleshoot security error codes on secure websites. But that may not be obviously useful, so keep us in the loop.

You can check if there is more detail available about the issuer of the certificate.

• click the "Advanced" button show more detail
• click the blue error text (SEC_ERROR_UNKNOWN_ISSUER) to show the certificate chain
• click "Copy text to clipboard" and paste the base64 certificate chain text in a reply

If clicking the blue error text doesn't provide the certificate chain then try these steps to inspect the certificate.

• open the Servers tab in the Certificate Manager
  • Options/Preferences -> Privacy & Security
    Certificates: View Certificates -> Servers: "Add Exception"
• paste the URL of the website (https://xxx.xxx) in it's Location field

Let Firefox retrieve the certificate -> "Get Certificate"

• click the "View" button and inspect the certificate

You can find detail like the issuer of the certificate and intermediate certificates in the Details tab.