HTTP 500 Error on deployment to new server

I have an existing application that is working on a Debian server on AWS. I recently created a fresh debian image on Linode.

Accessing the new server gives the following error:

[Thu Jun 08 09:01:09.014041 2023] [php:error] [pid 64967] [client xxx.xxx.xxx.xxx:21632] PHP Fatal error: Uncaught Error: Call to undefined method sec1_Login_apl::controle() in /var/www/html/mysite/sec1_Login/index.php:3386\nStack trace:\n#0 {main}\n thrown in /var/www/html/mysite/sec1_Login/index.php on line 3386

Does anyone know what could be causing this?
Regards
Craig

Are you sure you uploaded the runtime as well?

Hi Auducom,

By Runtime do you mean setting up the production environment?

Regards
Craig

No, I mean the huge set of files that is required to have the system to work. If you use apache, also look in the error logs. It is possible that required packages are not enabled.