hi jjpjjpjjp, this means that the webserver you're trying to reach is vulnerable to the recently published logjam vulnerability: http://arstechnica.com/security/2015/05/https-crippling-attack-threatens-tens-of-thousands-of-web-and-mail-servers/ please report that to webmaster of the site in question to fix that issue...

https://weakdh.org/

This seems to directly refer to my problem, just to make sure, I am running 64 bit windows 8.1 and a newer browser, it would still affect me?

this is a vulnerability in the configuration of web-servers, that allows downgrading the encryption levels of connections so that third parties can listen in (so it will need to be fixed by the administrators of each affected webservers). new browser versions should show you a warning message like the one you have referenced and block any connections to affected servers.

Well thank you very much for sharing this knowledge with me, I will do what I can to correct it, and I will contact the webmasters a.s.a.p.

Note that users with the current and older Firefox releases can toggle these prefs to false on the about:config page to disable the cipher suites that are involved with the Logjam vulnerability.

• security.ssl3.dhe_rsa_aes_128_sha
• security.ssl3.dhe_rsa_aes_256_sha

• Bug 1138554 - NSS accepts export-length DHE keys with regular DHE cipher suites

Logjam: How Diffie-Hellman Fails in Practice:

• https://weakdh.org/

Thanks for the update, I'm going to go ahead and access that now and see if that changes anything about the certificate.

well after toggling both to false, I still get the error on the secure page I am accessing. I have, however, found a solution, for now, my Google Chrome has not been affected by this weak dh error and I can use it to access that specific page and probably any other page with such an error.

Edit: hold on. I had picked the wrong ones. I did what you said and that solved it perfectly. Thank you for your solution! I can now access the secure page using my mozilla browser.