Adapted Code for Django 1.11 and Python 3,

updated the CKEditor

src/content/static/js/ckeditor/config.js

@@ -1,5 +1,5 @@
 /**
- * @license Copyright (c) 2003-2015, CKSource - Frederico Knabben. All rights reserved.
+ * @license Copyright (c) 2003-2017, CKSource - Frederico Knabben. All rights reserved.
  * For licensing, see LICENSE.md or http://ckeditor.com/license
  */
 
@@ -8,9 +8,6 @@ CKEDITOR.editorConfig = function( config ) {
 	// For complete reference see:
 	// http://docs.ckeditor.com/#!/api/CKEDITOR.config
 
-    config.width  = "960px";
-    config.height = '50vh';
-
 	// The toolbar groups arrangement, optimized for two toolbar rows.
 	config.toolbarGroups = [
 		{ name: 'clipboard',   groups: [ 'clipboard', 'undo' ] },
@@ -34,15 +31,8 @@ CKEDITOR.editorConfig = function( config ) {
 	config.removeButtons = 'Underline,Subscript,Superscript';
 
 	// Set the most common block elements.
-	config.format_tags = 'p;h2;h3;h4;h5;pre';
-    config.contentsCss = '/static/css/kasu.css';
-    config.allowedContent = true;
+	config.format_tags = 'p;h1;h2;h3;pre';
 
 	// Simplify the dialog windows.
-	config.removeDialogTabs = 'link:advanced';
-
-    //enable uploading
-	config.filebrowserBrowseUrl = '/ckeditor/browse/';
-    config.filebrowserUploadUrl = '/ckeditor/upload/';
-
-};
+	config.removeDialogTabs = 'image:advanced;link:advanced';
+};