FF is complaining because either (or both)
1) the SSL certificate is self-signed
2) the URL (domain) doesn't quite match (i.e., the SSL certificate is for SERVER.lunarWHATEVER.com, and you're logging in to login.SERVER.lunarWHATEVER.com)

Neither is anything to worry about. Just tell your browser to go ahead and accept the certificate and proceed. You understand and accept "the risk" (which isn't any risk at all -- FF is just trying to protect you from some common attacks).

If you're not doing anything that requires/needs a secure connection you can use http://yourdomain.com:2082 and you won't get that error.

Please check the firewall settings on your computer if you had installed any security firewall or antivirus software which causing to block access to the ports required for cPanel, WHM, and webmail to load. These ports are 2086 and 2087 as defined in cpanel hosting server. If you had not permit entry access for this port on your compute, please include it in your permission list of your firewall setting.

And second possible issue might be you have entered wrong username or password to cpanel or WHM for more than 5 times in a roll, then our server firewall will blocked your IP for accessing it again, this security measure is to prevent anyone trying to hack into our account by trying multiple times of password or username guessing. If it happened that you know you have entered the wrong username or password for more than 5 times in a roll, please submit a support ticket via the helpdesk to have your IP unblocked from the server firewall
www.discountsvu.com

Also, just to add to Marian's fine reply - this page goes into this topic in more detail:

http://wiki.lunarpages.com/Login_Certificate_Errors

 

Coloring aside, it says Firefox right on the error:


Firefox is user configurable for theme and display. Either those were changed or someone had time to color it in paint/photoshop