Thank you for your replies.
So one issue for example, when trying to open the modules folder I get this message:
Oops... looks like an unexpected error occurred.
Attempted to call an undefined method named "loadEnv" of class "Symfony\Component\Dotenv\Dotenv".
[Symfony\Component\Debug\Exception\UndefinedMethodException 0]
And in the server logs, I see:
Error GET /dan/index.php/improve/modules/manage?_token=bUWXWlH_Ze-2C6zw3gGZom4SXt9afGk_Ey-0ND5cFrQ HTTP/1.1
and
AH01071: Got error 'PHP message: PHP Warning: Invalid argument supplied for foreach() in /var/www/vhosts/gamer-tech.co.uk/httpdocs/modules/prestablog/class/news.class.php on line 336'
And before I lost access to the Module Manager, I couldn't update any module.