The requested URL was not found on this server

and also your router may be

.htaccess:
RewriteEngine on

RewriteCond $1 !^(index\.php|resources|robots\.txt)
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php/$1 [L,QSA]

Router:
$route['default_controller'] = 'welcome';

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