Hi,
you need to find the file uji-countdown.php and add the line
wp_enqueue_script('jquery');
in the following function. It′s the last function in the file.
function ujic_scripts_register() {
wp_register_style('ujiStyleCount', UJI_PLUGIN_URL . '/css/jquery.countdown.css');
wp_register_script('UJI_js_countdown', UJI_PLUGIN_URL . '/js/jquery.countdown.js', array('jquery'), '1.0', true);
wp_enqueue_script('jquery');
}
Hope this helps.