在一个 CodeIgniter controller session 是空的，在其他所有作品

Question

I developed this functionality locally on my laptop and all worked well, but when I uploaded changes on the server, I received an issue.

The check_admin_auth() function checks session variable and it is NULL when it calls from my controller (all other controllers in the project with the same code works well).

<?php if (!defined('BASEPATH')) exit('No direct script access allowed');

class Ctransaction extends CI_Controller
{
    public function __construct()
    {
        parent::__construct();
        $this->auth->check_admin_auth(); // this function
         /* checks one session item to check is user logged and admin or not,
            if not - redirects to login page. But in my case redirecting doesn't apply,
            I see just white screen, page status 200. */
        $this->db->query('SET SESSION sql_mode = ""');
    }

    public function index()
    {
        // some code here
        $content = $this->parser->parse('gltransaction/list', $data, true);
        $this->template->full_admin_html_view($content);
    }

    public function ajaxLoadGLTransactions()
    {
        // some code here
        echo json_encode($result);
    }
}

Please, can you help me to find where the problem is? I think that's settings in php.ini or in the same place, but I didn't find a reason.

I tried to modify /system/libraries/Session/Session.php as it was recommended in web, but it didn't help.

Files with sessions are created in folder /application/ci_sessions and they stored all necessary data, but for some reason, my controller doesn't load it and returns on its page session with only one field - __ci_last_regenerate .

The library session is loaded in autoloader in configuration file.

Cookies are the same on working pages and on page of my controller.

CI Version 3.1.4

PHP Version 7.2.32

Answer 1

The problem was that before <?php I've added one more line. The file of controller was like:

// empty line without anything
<?php if (!defined('BASEPATH')) exit('No direct script access allowed');
// and all other code

Didn't think that it can make sense!