Fatal error: Call to undefined method Artist::_ci_assign_to_models()

[eluser]tmac[/eluser]
hi, I am creating a page to force download a csv file. I have the error in the topic when i use the following codes.

Code:

// Load the DB utility class
        $this->load->dbutil();

        $query = $this->db->query("SELECT first_name, last_name, addr_line1, addr_line2, city, state, zipcode, phone FROM ".$this->config->item('users_tbl'));

        $delimiter = ",";
        $newline = "\r\n";


            $backup =& $this->dbutil->csv_from_result($query, $delimiter, $newline);
            // Load the download helper and send the file to your desktop

            $this->load->helper('download');
            force_download('user_address.csv', $backup);

Any help on this matter would be greatly appreciated. Thanks