[wolfgang1983]

You could try the following to debug your problem:

PHP Code:

<?php

class Forum extends CI_Controller {

    public function __construct() {
        parent::__construct();
        $this->load->model('model_forum');
        $this->load->library('form_validation');
    }

    public function index() {
        $data['forum_user_total_votes'] = 'Your Rep ' .  $this->model_forum->get_forum_user_reputation();
        $data['total_votes'] = $this->model_forum->get_forum_question_reputation();

        $this->load->view('common/header');
        $this->load->view('forum/forum_question_demo', $data);
        $this->load->view('common/footer');
    }

    public function down_vote() {
        

        $this->form_validation->set_rules('down_vote', 'Down Vote');

        if ($this->form_validation->run() == FALSE) {

            echo "Does Not Work";

            var_dump($_POST);

            // This should give you details on why the form was rejected:
            var_dump(validation_errors());

            //redirect('forum');

        } else {

            echo $this->input->post('down_vote');

            $this->model_forum->update_forum_question_down_vote();
            $this->model_forum->update_forum_user_reputation_down_vote();
                
            redirect('forum');
        }
    }
} 


Thank you for tip in the set_rules for some reason to make it work requires a third part i.e required and then it worked. Unsure why need that third part to make it work?

Code:

$this->form_validation->set_rules('down_vote', 'Down Vote', 'trim|required');

Will not work if just have

Code:

$this->form_validation->set_rules('down_vote', 'Down Vote');