I've been encountering an error thats making me unable to access Weasyl, Sofurry, e621 etc but its allowing me to go on inkbunny, pixiv, deviantart, and obviously FA.

"This Connection is Untrusted

You have asked Firefox to connect securely to e621.net, but we can't confirm that your connection is secure.

Normally, when you try to connect securely, sites will present trusted identification to prove that you are going to the right place. However, this site's identity can't be verified.
What Should I Do?

If you usually connect to this site without problems, this error could mean that someone is trying to impersonate the site, and you shouldn't continue."

I tried clicking on the "I understand the risks" option it gives on the page under all that info, clicked "Add exception" and Confirm Security Exception and that did nothing so I looked up ways to fix it and none of them have worked, they were:

-Make sure the time on the computer is correct (Time is correct)
-Go to options, then click advanced, then network, settings, and have it say "no proxy"
-Go to the help menu, then click troubleshooting info, click on show folder, when in the folder delete "cert8" and restart firefox and it will generate a new version of the file.

I even restarted firefox fresh with the option under troubleshooting to do so and that did nothing to solve the problem.
Restarting my computer and my router/modem also did nothing as well.

Any help that can be given to solve this problem would greatly be appreciated. If these problems can't be solved, I'm just going to dump firefox.

[Edit]

Managed to resolve the issue and added some exceptions so my antivirus won't go nuts and force firefox to block access to the sites.