Community Auth - a database error when logging in

I have installed Community Auth with CodeIgniter 3.1.4 and I got the same error : 

Column 'id' cannot be null [...] Filename: third_party/community_auth/models/Auth_model.php Line Number: 90

After reading this thread, I checked my CI session configuration (it was OK) and then, I started to debug.

It seems that after this line (libraries/Authentication.php:693

PHP Code:

$session_id = $this->CI->session->sess_regenerate( config_item('sess_regenerate_destroy') ); 


the value of $session_id is null.

But, if I replace this line by :

PHP Code:

$this->CI->session->sess_regenerate( config_item('sess_regenerate_destroy') );
$session_id = $this->CI->session->session_id; 


 everything is working well.

Do you have any idea why I get this error ?

What is your session config look like? Have you set base_url in config/config? Did you properly set up your encryption key?

Expert Website Development - Temecula, CA
Community Auth For CodeIgniter 3