Firefox cannot connect securely because the site uses an older insecure version of the SSL protocol
This article describes why you can get the message "Firefox can't connect securely to (site name) because the site uses an older, insecure version of the SSL protocol" when trying to go to certain secure (https) sites.
Support for SSL v2 (Secure Sockets Layer 2.0) is disabled by default. While most sites have moved to a better encryption protocol, some have not. If you access a site that only supports SSL v2, you will receive the above error in Firefox.
You should contact the owner of the site, and ask them to a support a newer encryption protocol. You can also report the site to the Firefox developers by opening the Help menu and choosing Report Broken Website....
If you must access the site, you can turn on SSL v2 support.
SSL v2 is disabled for a reason. It is a flawed security mechanism, and any information you send to an SSL v2 site could be intercepted by someone else.
In the address bar, type about:config and press EnterReturn.
The about:config "This might void your warranty!" warning page may appear. Click I'll be careful, I promise!I accept the risk! to continue to the about:config page.
In the Filter: box, type ssl2.
Double-click each preference line to set it to true.
With SSL v2 enabled, you should now be able to access the site.