我正在尝试使用一个旧插件http://wordpress.org/extend/plugins/wp-ecards/ （我不是插件作者）当我试图在网站上查看电子卡时，在php错误日志和一个空白屏幕中出现此错误：

 Failed opening \'\' for inclusion (include_path=\'.:/usr/share/php:/usr/share/pear\')
 in /home/public_html/demo/wp-content/plugins/wp-ecards/ft-wp-ecards.php on line 171

I don\'t know what is happening. Is this plugin trying to load the pear library? Any ideas?

function init_wpecards_viewcard(){
    global $wp_query;
    if ( isset($wp_query->query_vars[\'ft_wpecards_view\']) ){
        if ( $ft_wpecards_parentpost = ft_wpecards_get_post_id($wp_query->query_vars[\'card\']) ){
            if ( ft_wpecards_get_post_type($wp_query->query_vars[\'card\']) == \'post\' ) {
                query_posts("p=".$ft_wpecards_parentpost."&ft_wpecards_view=1&card=".$wp_query->query_vars[\'card\']);
                include(get_single_template());  
                //exit;
            }else{


    query_posts("page_id=".$ft_wpecards_parentpost."&ft_wpecards_view=1&card=".$wp_query->query_vars[\'card\']);
                    include(get_page_template()); //LINE 171
                    //exit;
                }
            }else{
                include(get_404_template());
            }
            exit;
        }
        //die(\'tr\');
    }
    add_action(\'template_redirect\',\'init_wpecards_viewcard\');