Why am I suddenly getting a “Blocked loading mixed active content” issue in Firefox?

Question

This morning, upon upgrading my Firefox browser to the latest version (from 22 to 23), some of the key aspects of my back office (website) stopped working.

Looking a

Answer 1

I had this same problem because I bought a CSS template and it grabbed a javascript an external javascript file through http://whatever.js.com/javascript.js. I went to that page in my browser and then changed it to https://whatever... using SSL and it worked, so in my HTML javascript tag I just changed the URL to use https instead of http and it worked.