Fatal error: Cannot declare class WP_Metadata_Lazyloader, because the name is already in use in /wp-includes/class-wp-metadata-lazyloader.php on line 32

Fatal error: Uncaught Error: Class "WP_Translation_Controller" not found in /web/clients/www/4/6/9/1/szoz.idsl.pl/wp-includes/l10n.php:801 Stack trace: #0 /web/clients/www/4/6/9/1/szoz.idsl.pl/wp-includes/l10n.php(960): load_textdomain('default', '/web/clients/ww...', 'pl_PL') #1 /web/clients/www/4/6/9/1/szoz.idsl.pl/wp-includes/class-wp-fatal-error-handler.php(49): load_default_textdomain() #2 [internal function]: WP_Fatal_Error_Handler->handle() #3 {main} thrown in /wp-includes/l10n.php on line 801