Your server maybe updated to PHP 8 and some functions may not be compatible with your existing code. To solve this, turn on debug in wp-config, navigate once to your website, and inspect the contents in wp-contents/debug.log.
Alternatively, you can post the content in that log here and we can further help.
Thank you for the advice.
The reported error is: Fatal error : __autoload() is no longer supported, use spl_autoload_register() instead in /home/vol2_6/epizy.com/epiz_20991517/htdocs/wp-includes/compat.php on line 502
but no idea which file needs the change. Very odd because I run the script on another server without a problem.