CKEditor.

The error came from some script in Application.js

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

@@ -0,0 +1 @@
+(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(){this.getContentElement('general','content').getInputElement().setValue('')},onOk:function(){var text=this.getContentElement('general','content').getInputElement().getValue();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()}}]}]}})})();