"Json" as controller name does not work

Strange I just ran it with CodeIgniter 3.1.11 with no errors without using routes.

Maybe something to do with your routing.

Well my full routing file is: 

PHP Code:

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

$route['xml']                   = 'xml';
$route['xml/(:any)']            = 'xml/$1';

$route['json']                  = 'json';
$route['json/(:any)']           = 'json/$1';

$route['dashboard']             = 'members';
$route['account']               = 'members/account';
$route['login']                 = 'members/login';
$route['register']              = 'members/register';

$route['members']               = 'members';
$route['members/(:any)']        = 'members/$1';

$route['(:any)']                = 'pages/$1';

$route['default_controller']    = 'pages';

$route['404_override']          = '';
$route['translate_uri_dashes']  = FALSE; 


I' ll check if there's something wrong with the .htaccess file.

---

//Life motto
if (sad() == true) {
     sad().stop();
     develop();
}