comment 0

ReferenceError: $ is not defined

It means jQuery library either not added or it is not properly added hence link is broken. Those plugins which uses jQuery functions throw error

ReferenceError: $ is not defined 

on the console as they are unable to find it.

To avoid such an issue its always better to use a CDN. CDN stands for content delivery network. Google has one for jQuery.

<script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/jquery/2.0.0/jquery.min.js"></script>

Or add jQuery directly by downloading it from following link.

//ajax.googleapis.com/ajax/libs/jquery/2.0.0/jquery.min.js