localhost is currently unable to handle this request. HTTP ERROR 500

I have this error when i am trying to access a website from wamp, it is done in codeigniter.
Error:

Code:

localhost is currently unable to handle this request. HTTP ERROR 500

homeindex controller

Code:

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

class HomeIndex extends CI_Controller {

   public function __construct(){
       parent:: __construct();
       $this->load->helper('html');
       $this->load->helper('form','url','file');
       $this->load->library('session','upload');
   }

   public function index()
   {  
       //$this->load->view('coming_soon');
       $this->load->view('homeIndex');
   }
}

route

Code:

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

I am able to access other website which are not done using any frameworks.
This website is done using codeigniter. I am not able to access the website.
Can anyone tell me what is the problem?