CKEditor.

The error came from some script in Application.js

public/javascripts/ckeditor/_source/plugins/embed/dialogs/embed.js

@@ -0,0 +1,65 @@
+/*
+Copyright (c) 2003-2009, CKSource - Frederico Knabben. All rights reserved.
+For licensing, see LICENSE.html or http://ckeditor.com/license
+*/
+
+(function()
+{
+	CKEDITOR.dialog.add( 'embed', function( editor )
+		{
+			return {
+				title : editor.lang.embed.title,
+        
+				minWidth : CKEDITOR.env.ie && CKEDITOR.env.quirks ? 368 : 350,
+				minHeight : 240,
+
+				onShow : function()
+				{
+					// Reset the textarea value.
+					this.getContentElement( 'general', 'content' ).getInputElement().setValue( '' );
+				},
+
+				onOk : function()
+				{
+					// Get the textarea value.
+					var text = this.getContentElement( 'general', 'content' ).getInputElement().getValue();
+
+					// Inserts the html.
+					this.getParentEditor().insertHtml( text );
+				},
+
+				contents :
+				[
+					{
+						label : editor.lang.common.generalTab,
+						id : 'general',
+						elements :
+						[
+							{
+								type : 'html',
+								id : 'pasteMsg',
+								html : '<div style="white-space:normal;width:340px;">' + editor.lang.embed.pasteMsg + '</div>'
+							},
+							{
+								type : 'html',
+								id : 'content',
+								style : 'width:340px;height:170px',
+								html :
+									'<textarea style="' +
+										'width:346px;' +
+										'height:170px;' +
+										'resize: none;' +
+										'border:1px solid black;' +
+										'background-color:white">' +
+									'</textarea>',
+								focus : function()
+								{
+									this.getElement().focus();
+								}
+							}
+						]
+					}
+				]
+			};
+		});
+})();