In order to get to the bottom of the problem, I need to see the logs from the server. You can retrieve them via your hosting panel (please refer to your hoster if you don’t know where to get them) - this option actually is preferable, or you can add the following code to the beginning of the page that is not working (after <?php tag):
ini_set('display_errors', '1'); ini_set('display_startup_errors', '1'); error_reporting(E_ALL);
then reload the page. If there’s an error message appeared, please share it while reporting the issue, if not - use option 1. I won’t be helping unless logs are provided.
Please, while sharing the logs, make sure you have removed all the sensitive data (passwords, logins, etc.).
! After troubleshooting, don’t forget to remove the lines you added !
Double (or triple, if needed) check that you have uploaded all the files to your webserver.