我们正在WP网站上使用上游模板。在上次WP 4.8更新之后，我们在管理面板上收到一条错误消息，这不允许我们使用幻灯片。错误如下：

致命错误：未捕获错误：函数名必须是/var/www/vhost/calamburtetro中的字符串。com/home/html/wp-content/themes/UpStream/lib/Admin。php:248堆栈跟踪：#0/var/www/vhost/calamburteatro。com/home/html/wp-content/themes/UpStream/lib/Admin。php（451）：materadmin->form\\u callback（\'featuredposts\\u s…\'，Array）#1/var/www/vhost/calamburteatro。com/home/html/wp-content/themes/UpStream/lib/Admin。php（388）：材料管理->选项页面内容项（数组）#2/var/www/vhost/calamburteatro。com/home/html/wp-content/themes/UpStream/lib/Admin。php（324）：材料管理->选项页面内容（）#3/var/www/vhost/calamburteatro。com/home/html/wp-includes/class-wp-hook。php（298）：材料管理->材料操作（“”）#4/var/www/vhost/calamburetatro。com/home/html/wp-includes/class-wp-hook。php（323）：WP\\u Hook->apply\\u filters（“”，Array）#5/var/www/vhost/calamburteatro。com/home/html/wp-includes/plugin。php（453）：WP_Hook->do_action（数组）#6/var/www/vhost/calamburteatro。com/home/html/wp-admin/admin。php（222）：do\\u action（\'appearance\\u page…\'）\\7/in/var/www/vhost/calamburteatro。com/home/html/wp-content/themes/UpStream/lib/Admin。php在线248

admin上的第248行。php是：$callback[0]->$callback[1]();

整个功能代码是：

function form_callback ($name, $attributes = array())
    {
        if(isset($attributes[\'callback\']) && is_array(($attributes[\'callback\']))) {
            $callback = $attributes[\'callback\'];
            $callback[0]->$callback[1]();
        } else {
            if(function_exists($name)) {
                return $name($attributes);
            }
        }

    }