title: React 0.13.x _classCallCheck() in DefaultRoute 'Cannot call a class as a function’
body: <p>I’m using React 0.13.3 with Webpack 1.9.5 and traceur-loader 0.6.3 (tried babel-loader before that), getting TypeError thrown by _classCallCheck() in DefaultRoute 'Cannot call a class as a function’. I don't see where I'm calling a class as a function. This is what my routes look like:</p>
  
  <pre><code>    var Application = require('./components/Application');
      var Home = require('./components/Home');
      var About = require('./components/About');
      var MainFeedVideos = require('./components/MainFeedVideos');
      var MyUploads = require('./components/MyUploads');
      ...
      var routes = (
              //logged out content
              &lt;Route flux={flux} handler={Application}&gt;
                  &lt;DefaultRoute handler={Home} /&gt;
                  &lt;Route name='about' handler={About}/&gt;
                  ...
                  //logged in content
                  &lt;Route path='/' name='home' handler={Home}&gt;
                      &lt;DefaultRoute handler={MainFeedVideos} /&gt;
                      &lt;Route name='my-videos' handler={MyUploads}/&gt;
                      ...
                  &lt;/Route&gt;
              &lt;/Route&gt;);
  
      Router.run(routes, Router.HistoryLocation, function (Handler) {
          React.render(&lt;Handler/&gt;, document.getElementById('content'));
      });
  </code></pre>
  
  <p>Anyone had this issue before?</p>