Fix a "Secure Connection Failed" - Firefox/Mozila

1. In the Location bar, type about:config and press Enter. The about:config "This might void your warranty!" warning page may appear.
2. Click I'll be careful, I promise! to continue to the about:config page.
3. copy the next security.ssl.enable_ocsp_stapling and paste it in the search field
4. double-click on it to make it false
5. close the page, exit firefox and restart it.

probably the problem is the web site, when the problem resolved by the site, go back and switch the setting to true again.