I have uploadeed the website to a new server, currently using ulsteinminilager.com during testing. I've been struggling for hours to get php working in the submit order procedure. I get "Generic error".

PHP is apparently working: I test local php settings of the php engine (version 7.2.5) with the command "php e:\ulsteinminilager\admin\login.php, but the php error log writes:

"[28-Jan-2023 19:35:18 UTC] PHP Warning: require_once(../res/x5engine.php): failed to open stream: No such file or directory in E:\Ulsteinminilager\admin\includes.php on line 3
[28-Jan-2023 19:35:18 UTC] PHP Fatal error: require_once(): Failed opening required '../res/x5engine.php' (include_path='.;c:\php\includes') in E:\Ulsteinminilager\admin\includes.php on line 3"

If I try the web browser on ulsteinminilager.com/admin/login.php I get error "404 - File or directory not found." By the way, the same 404 error comes up regardless of where I place a php file using test.php (I attach a log of response dump) with content:

<?php
phpinfo();
?>

Thus, may it be a setting in IIS I have missed?