Fatal error: Uncaught Error: Call to undefined function is_main_site() in /var/www/www-root/data/www/pp.cdn-img.wwtfm.ru/wp-includes/update.php:956 Stack trace: #0 {main} thrown in /var/www/www-root/data/www/pp.cdn-img.wwtfm.ru/wp-includes/update.php on line 956