>Press F12 and depending of the browser debug the script.
>First see if you have any error messages in console.

Thanks, that was going to be my next question: how to debug this :)

This error is showing:

jQuery.Deferred exception: a.indexOf is not a function TypeError: a.indexOf is not a function
    at r.fn.load (http://localhost:51730/jquery-3.1.0.min.js:4:18717)
    at HTMLDocument.<anonymous> (http://localhost:51730/AboutUs.aspx:13:23)
    at j (http://localhost:51730/jquery-3.1.0.min.js:2:29568)
    at k (http://localhost:51730/jquery-3.1.0.min.js:2:29882) undefined

Of course, that isn't very helpful to me :(

Google here I come