Uncaught TypeError: Cannot read property ‘$’ of undefined
at CKEDITOR.focusManager.g (ckeditor_39a28802.min.js:224)
at CKEDITOR.focusManager. (ckeditor_39a28802.min.js:225)
at ckeditor_39a28802.min.js:26
how to upgrade the version of CKeditor to 4
thanks