CKeditor instance is null or undefined?-Collection of common programming errors

It could be that the instances variable is simply undefined at that time. Depending on what you really want to do with the editor, I suggest that you do the on key bindings and other such things inside instanceReady, which is a CKEditor event.

$(document).ready(function () {  
    // You can define it before replacing the editor
    CKEDITOR.on('instanceReady', function(evt){
        // Do your bindings and other actions here for example
        // You can access each editor that this event has fired on from the event
        var editor = evt.editor;
    });

   // replace editor
    var editorShort = CKEDITOR.editor.replace('popup_editor1');
});

See the documentation at http://docs.ckeditor.com/#!/api/CKEDITOR-event-instanceReady

Originally posted 2013-11-09 19:45:42.