title: TypeError: a.apply is not a function
body: <p>I am following a backbone.js for beginners tutorial, and I've got stuck at the first hurdle. I get the error <code>TypeError: a.apply is not a function</code> in  firebug (Firefox 20.0.1).
  I have the following code:</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html lang="en"&gt;
  &lt;head&gt;
  &lt;title&gt;Backbone Test&lt;/title&gt;
  &lt;link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/2.1.1/css/bootstrap.min.css" /&gt;
  &lt;meta charset="utf-8" /&gt;
  &lt;/head&gt;
  &lt;body&gt;
  
      &lt;div class="container"&gt;
          &lt;h1&gt;User Manager&lt;/h1&gt;
          &lt;hr /&gt;
          &lt;div class="page"&gt;&lt;/div&gt;
      &lt;/div&gt;
  
      &lt;script src="//cdnjs.cloudflare.com/ajax/libs/jquery/1.8.2/jquery.min.js" type="text/javascript"&gt;&lt;/script&gt;
      &lt;script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.4.2/underscore-min.js" type="text/javascript"&gt;&lt;/script&gt;   
      &lt;script src="//cdnjs.cloudflare.com/ajax/libs/backbone.js/0.9.2/backbone-min.js" type="text/javascript"&gt;&lt;/script&gt;
      &lt;script&gt;
          var Router = new Backbone.Router.extend({
              routes: {
                  '': 'home'
              }    
          });
  
          var router = new Router();
  
      &lt;/script&gt;
  
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>I am using these older versions of <em>jquery</em>, <em>underscore</em> and <em>backbone</em> because they are the versions used in the tutorial. I tried using current versions of all, and I get a similar error: "TypeError: <em>i</em>.apply is not a function".</p>
  
  <p>The error happens when an instance of Router is created, ie the line: <code>var router = new Router();</code> above.</p>
  
  <p>Is the error to do with my set-up? WAMP, or the code, or the libraries? I can't understand it as it's the same to the letter as the <a href="https://gumroad.com/l/backbone-beginner-screencast" rel="noreferrer">tutorial</a>.</p>