File not found in PHP

Question

I installed a script and is working properly, but on the site there is a restricted area and when logging in, the site drops and gives the following error:

An Error Was Encountered Unable to load the requested file: .. /.. /public_html/themes/private/template.php

Follows the code of the page in question:

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

/**
 * Base Private Class - used for all private pages
 */
class Private_Controller extends MY_Controller {

    /**
     * Constructor
     */
    function __construct()
    {
        parent::__construct();

        $this->load->library('currencys');

        // must be logged in
        if ( ! $this->user)
        {
            if (current_url() != base_url())
            {
                // store requested URL to session - will load once logged in
                $data = array('redirect' => current_url());
                $this->session->set_userdata($data);
            }

            redirect('login');
        }

        // prepare theme name
        $this->settings->theme = strtolower($this->config->item('private_theme'));

        // set up global header data
        $this
            ->add_css_theme( "{$this->settings->theme}.css" )
            ->add_js_theme( "{$this->settings->theme}_i18n.js", TRUE );

        // declare main template
        $this->template = "../../{$this->settings->root_folder}/themes/{$this->settings->theme}/template.php";
    }

}