404 Override Not Working

If you create the file: application/core/MY_Exceptions.php with the following code what happens?

PHP Code:

<?php


class MY_Exceptions extends CI_Exceptions {

    function __construct() {

        parent::__construct();

    }

    public function show_404($page = '', $log_error = TRUE)
    {
        if (is_cli())
        {
            $heading = 'Not Found';
            $message = 'The controller/method pair you requested was not found.';
        }
        else
        {
            $heading = '404 Page Not Found';
            $message = 'The page you requested was not found.';
        }

        
        if ($log_error)
        {
            log_message('error', $heading.': '.$page);
        }
        
        if( is_cli() ) {

            echo $this->show_error($heading, $message, 'error_404', 404);

        } else {
            header("HTTP/1.0 404 Not Found");
            
            
            header('location: http://www.yoursite.com/notfound');

        }
        exit(4); // EXIT_UNKNOWN_FILE
    }

} 


dont forget to replace www.yoursite.com with your applications domain. If it works you'll need to change how the base_url is passed in but this should be enough to see if it makes progress towards a solution.