Fatal error: Uncaught Error: Class 'IXR_Server' not found in /home/adminzst/public_html/zadaniexyz/wypozyczalnia/wp-includes/IXR/class-IXR-introspectionserver.php:9 Stack trace: #0 {main} thrown in /home/adminzst/public_html/zadaniexyz/wypozyczalnia/wp-includes/IXR/class-IXR-introspectionserver.php on line 9