Why do you need a to use an old Firefox 24 ESR version?

Firefox 31.7.0 ESR is current and Firefox 38.0.1 ESR has been released.

Can you post a link to a publicly accessible page (i.e. no authentication or signing on required)?

You can do a server test:

• https://www.ssllabs.com/ssltest/

For current Firefox releases (25 and later) you can look at this extension:

• SSleuth: https://addons.mozilla.org/firefox/addon/ssleuth

I see that my above reply is marked as unhelpful, so I assume that it doesn't help you for Firefox 24.

You should be able to see what TLS version and cipher suit current releases use. You can use the above posted extension or check that in the Security tab in the Web Console (Firefox/Tools > Web Developer). Firefox 24 only supports TLS 1.0 (security.tls.version.max = 1), so that only leaves you with the protocol to guess.

• http://kb.mozillazine.org/security.tls.version.*
• 0 means SSL 3.0, 1 means TLS 1.0, 2 means TLS 1.1, 3 means TLS 1.2 etc.

In Firefox 24 you only have the Security tab in "Tools > Page Info > Security" to see what cipher strength is used and you do not see what cipher suit is used. To find that you would have to disable all cipher suits by setting the security.ssls prefs to false and enable one at the time until you get a secure connection.

Thanks a lot for your reply Cor-El .

I tried the same thing at last  :) .