JavaScript runtime error: '$' is undefined

Question

So classic problem, but having a horrible time on finding the actual cause. Typically when I see this error it\'s because the jQuery reference is after code requiring it, or

Answer 1

In my case, the problem was that I was rendering my page over https but I was trying to request the JQuery file over http, which is blocked by many browsers for security reasons.

My fix was to change this...

...to this...

This causes the browser to download JQuery using the same protocol (http or https) as the page being rendered.