Fatal error: Cannot declare class WP_Metadata_Lazyloader, because the name is already in use in /home/nkornil2/domains/mediawave.pl/public_html/wp-includes/class-wp-metadata-lazyloader.php on line 32

Fatal error: Uncaught Error: Call to a member function set() on null in /home/nkornil2/domains/mediawave.pl/public_html/wp-includes/l10n.php:806 Stack trace: #0 /home/nkornil2/domains/mediawave.pl/public_html/wp-includes/l10n.php(900): load_textdomain('default', '/home/nkornil2/...', 'pl_PL') #1 /home/nkornil2/domains/mediawave.pl/public_html/wp-includes/class-wp-fatal-error-handler.php(47): load_default_textdomain() #2 [internal function]: WP_Fatal_Error_Handler->handle() #3 {main} thrown in /home/nkornil2/domains/mediawave.pl/public_html/wp-includes/l10n.php on line 806