How to configure Session with Files

Hello,
I try to use session_data with

PHP Code:

$config['sess_driver'] = 'files';// and 
$config['sess_save_path'] = 'cache_session'; // with directory 'cache_session' with all the rights (chmod (777)). I try with cache_session/ and idem
$config['sess_expiration'] = 7200;
$config['sess_match_ip'] = FALSE;
$config['sess_time_to_update'] = 300;
$config['sess_regenerate_destroy'] = FALSE; 


But, when i'm declaring a session variable and i try to use it in a page, i've this message :
"  touch(): Unable to create file cache_session\ci_session2f5e78f45e32a3fc8dadee822e0b8d68719d7e2a : failed to open stream: No such file or directory"
Error line number 234 in Sesssion_files_driver.php

At the first call of my controller named "Defaut", no problem for writing file for session and his name is (for example) : ci_session2f5e78f45e32a3fc8dadee822e0b8d68719d7e2a.
After, when i call my function (index) of the controller named "Debut" the view is loaded but an error appears.

I'm using session by database and all is all right and i wanted to try with files.

Can you help me please ? I do make a mistake somewhere

My Controller

PHP Code:

// i set my variable session in this controller for example. In the view associated, i can use the session variable. If i reload the page error appears
class Defaut extends CI_Controller
{
     private $vue = 'vue1' ;
     public function __construct() { parent::__construct(); }
     
  public function index()
 {
      // i defined a session variable named 'essai'
      $this->session->set_userdata('essai', 'coucou') ;
      $data['title'] = 'Titre' ;
      $this->load->view($this->vue, $data);
 }
} 


My Other controller

PHP Code:

class Debut extends CI_Controller
{
     private $vue = 'vue2' ;
     public function __construct() { parent::__construct(); }
     
     public function index()
    {
       $this->load->view($this->vue);
     }
} 


My other view name 'vue2'

PHP Code:

<?php echo 'value of var session :'.$this->session_userdata('essai') ; ?>
// error appears 


I resume :  i call my first view with my first controller named "Defaut" who create my session variable and then, i call my second controller named "Debut". The view is loaded and when i try to see the contain of my session varaible named "essai", error appears.

Thanks for your help.

Hello, 
I had the exact problem, try to load the url  helper before you use the session library, this seems to help.

---

PHP Code:

$this->load->helper('url');
$this->load->library('session'); 


i hope this fix the problem.