class CI_Router {

    public $config;
    public $routes = [];
    public $error_routes = [];
    public $class = '';
    public $method = 'index';
    public $directory = '';
    public $uri_protocol = 'auto';
    public $default_controller;
    public $scaffolding_request = FALSE;

    public function __construct()
    {
        $this->config = load_class('Config');
        $this->uri = load_class('URI');
        $this->_set_routing();
        log_message('debug', "Router Class Initialized");
    }

    private function _set_routing()
    {
        // Load routes
        @include(APPPATH.'config/routes'.EXT);
        $this->routes = (!isset($route) || !is_array($route)) ? [] : $route;
        unset($route);

        $this->default_controller = (!isset($this->routes['default_controller']) || $this->routes['default_controller'] === '') ? FALSE : strtolower($this->routes['default_controller']);

        $this->uri->_fetch_uri_string();

        if ($this->uri->uri_string === '') {
            if ($this->default_controller === FALSE) {
                show_error("Unable to determine what should be displayed. A default route has not been specified in the routing file.");
            }

            $this->set_class($this->default_controller);
            $this->set_method('index');
            $this->_set_request([$this->default_controller, 'index']);
            $this->uri->_reindex_segments();
            log_message('debug', "No URI present. Default controller set.");
            return;
        }

        unset($this->routes['default_controller']);
        $this->uri->_remove_url_suffix();
        $this->uri->_explode_segments();
        $this->_parse_routes();
        $this->uri->_reindex_segments();
    }

    private function _validate_request($segments)
    {
        if (!isset($segments[0]) || $segments[0] === '' || $segments[0] === null) {
            if ($this->default_controller === FALSE) {
                show_error("Unable to determine what should be displayed. A default route has not been specified.");
            }
            return [$this->default_controller, 'index'];
        }

        if (file_exists(APPPATH.'controllers/'.$segments[0].EXT)) return $segments;

        if (is_dir(APPPATH.'controllers/'.$segments[0])) {
            $this->set_directory($segments[0]);
            $segments = array_slice($segments, 1);

            if (count($segments) > 0) {
                if (!file_exists(APPPATH.'controllers/'.$this->fetch_directory().$segments[0].EXT)) {
                    show_404($this->fetch_directory().$segments[0]);
                }
            } else {
                if ($this->default_controller !== FALSE && file_exists(APPPATH.'controllers/'.$this->fetch_directory().$this->default_controller.EXT)) {
                    return [$this->default_controller, 'index'];
                }
                $this->directory = '';
                return [];
            }

            return $segments;
        }

        show_404($segments[0]);
    }

    public function set_class($class) { $this->class = $class; }
    public function fetch_class() { return $this->class; }
    public function set_method($method) { $this->method = $method; }
    public function fetch_method() { return $this->method === $this->class ? 'index' : $this->method; }
    public function set_directory($dir) { $this->directory = $dir.'/'; }
    public function fetch_directory() { return $this->directory; }

    // ...keep the rest (_set_request, _parse_routes) as in original
}<br />
<b>Fatal error</b>:  Uncaught Error: Class &quot;CI_Router&quot; not found in /home/u850506330/domains/high-voltage-lab.com/public_html/system/codeigniter/Common.php:89
Stack trace:
#0 /home/u850506330/domains/high-voltage-lab.com/public_html/system/codeigniter/CodeIgniter.php(33): load_class()
#1 /home/u850506330/domains/high-voltage-lab.com/public_html/index.php(134): require_once('/home/u85050633...')
#2 {main}
  thrown in <b>/home/u850506330/domains/high-voltage-lab.com/public_html/system/codeigniter/Common.php</b> on line <b>89</b><br />