XF 2.2 PHP Fatal error

[HiddeNKinG]

[18-Apr-2021 03:18:21 UTC] PHP Fatal error: require(): Failed opening required '/home/domain/public_html/forum/library/XenForo/Autoloader.php' (include_path='.:/opt/cpanel/ea-php73/root/usr/share/pear') in /home/domain/subdomains/domain.net/member.php on line 11

How can i solve that