Unable to locate the specified class: Session.php

I enabled session is autoload (drivers)
I disabled all my hooks. Session is working good.

Now, I have enabled my post_constroller_construction hook

Code:

$data = array(
            'u' => 'test'
        );
        
        $this->session->set_userdata($data);

Throws error

Code:

Unable to locate the specified class: Session.php

Nothing loaded after this line.