[Plugin: Widget CSS Classes] error notices

it shows error when using with any “widget logic” plugins, e.g. Notice: Undefined index: callback_wl_redirect in /var/www/projects/zdrojak/htdocs/public/soubory/plugins/widget-css-classes/includes/widget-css-classes.class.php on line 99

http://ww.wp.xz.cn/extend/plugins/widget-css-classes/