title: ckeditor - Uncaught TypeError: Cannot read property 'icons' of null
body: <p>When trying to use ckeditor for the first time.  ckeditor works, but when I try to add imageupload and uploadloadwidget plugins then I get the error:
  <strong><em>Uncaught TypeError: Cannot read property 'icons' of null</em></strong></p>
  
  <p>Does anyone have any ideas as to what might be causing it?</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>&lt;script src="//cdn.ckeditor.com/4.5.6/basic/ckeditor.js"&gt;&lt;/script&gt;
  
  &lt;script&gt;
      $(document).ready(function () {
          CKEDITOR.plugins.addExternal('imageupload', '/ckeditor/plugins/imageupload/');
          CKEDITOR.plugins.addExternal('uploadwidget', '/ckeditor/plugins/uploadwidget/');
          CKEDITOR.replace('htmleditor', {
              htmlEncodeOutput: true,
              extraPlugins: 'imageupload,uploadwidget'
  
          });
      });
  &lt;/script&gt;</code></pre>
  </div>
  </div>
  </p>