CSS not found

The lines in /plugin/hcard-widget/hCard_widget.php need to be changed to fix a broken path:

function hcard_add_css(){
        wp_register_style('hcard-style', plugins_url('hcard-widget/style.css', _FILE_));
        wp_enqueue_style('hcard-style');
        }

https://www.ads-software.com/extend/plugins/hcard-widget/