This tutorial shows you how to solve CKEditorFuncNum undefined.
To fix ckeditorfuncnum undefined or null you should add config.filebrowserUploadMethod = 'form' to the config.js file.
CKEDITOR.editorConfig = function( config ) {
//...
config.filebrowserUploadMethod = 'form';
};
When adding the config you can get the parameter CKEditorFuncNum return.