title: TypeError: window.tinyMCE.get(...) is null
body: <p>I am getting the following error when trying to edit a Wordpress page in visual editor on <a href="http://www.domaine-audubert.com" rel="nofollow">http://www.domaine-audubert.com</a>.      </p>
  
  <pre><code> TypeError: window.tinyMCE.get(...) is null
  
  
   window.tinyMCE.get( current_id ).setContent( content, {format: 'html'} );
  </code></pre>
  
  <p>The error seems to be located in wp-content/plugins/fusion-core/admin/page-builder/assets/js/js-wp-editor.js?ver=1.8.1 (line 173 col 7)</p>
  
  <p>In that column I can find this code:</p>
  
  <pre><code>            $(self).before('&lt;link rel="stylesheet" id="editor-buttons-css" href="' + fusionb_vars.includes_url + 'css/editor.css" type="text/css" media="all"&gt;');
  
              $(self).before(wrap);
              $(self).remove();
  
              new QTags(current_id);
              QTags._buttonsInit();
              switchEditors.go(current_id, options.mode);
  
              if( content &amp;&amp; options.mode == 'tmce' ) {
                  setTimeout( function() {
                      window.tinyMCE.get( current_id ).setContent( content, {format: 'html'} );
                  }, 1000);
              }
  
              $(wrap).on( 'click', '.insert-media', function( event ) {
                  var elem = $( event.currentTarget ),
                      editor = elem.data('editor'),
                      options = {
                          frame:  'post',
                          state:  'insert',
                          title:  wp.media.view.l10n.addMedia,
                          multiple: true
                      };
  
                  event.preventDefault();
  
                  elem.blur();
  
                  if ( elem.hasClass( 'gallery' ) ) {
                      options.state = 'gallery';
                      options.title = wp.media.view.l10n.createGalleryTitle;
                  }
  
                  wp.media.editor.open( editor, options );
                  //hide insert from URL
                  $('.media-menu a:contains(Insert from URL)').remove();
              });
  
          }
      });
  }
  </code></pre>
  
  <p>})( jQuery, window )</p>
  
  <p>But I have no idea where the error comes from. Is this a common problem and what can I do about it?</p>