Error: 404 Page not found in codeigniter Bonfire logs file on every page load -

i new using codeigniter. i'm using codeigniter bonfire framework creating application. every time when load page, logs file generate error:

error - 2015-06-10 05:30:12 --> 404 page not found -->
error - 2015-06-10 05:30:18 --> 404 page not found -->

how solve error , create 404 page in application?

here routes

$route['default_controller'] = "restaurant";  $route['404_override'] = '';  $route['login'] = 'users/login';  $route['register'] = 'users/register';  $route['logout'] = 'users/logout';