Upgrading to Phalcon 3 broke the existing site

My problem started right after I upgraded PHP to Version 7 and Phalcon to Version 3.

Problem

I m getting blank page, no error messages (Error is turned on), no `500 Internal server' error in console. The site used to work flawlessly before.

Is application made with previous version of phalcon not compatible with Phalcon 3?

I have following controller IndexController.php

namespace RealEstate\Property\Controllers;

use \Phalcon\Mvc\Controller;
use \Phalcon\Mvc\View;
use  RealEstate\Common\Models as CommonModels;

class IndexController extends Controller
{
   public function initialize(){
          //Code here
   }

   public function indexAction(){
       $this->view->setRenderLevel(View::LEVEL_ACTION_VIEW);

       $this->view->setVar("total_properties", $this->utils->getTotalProperties());    
       $this->view->pick("index");
       echo "HELLO WORLD";
   } 
}

The index action doesnot render anything, but yes HELLO WORLD is printed, so there seems there is no errors in code above that line.

My bootstrap index.php

namespace RealEstate;

use \Phalcon\Mvc\Application;
use \Phalcon\DI\FactoryDefault;
use \Phalcon\Loader;
use \Phalcon\Mvc\Router;
use \Phalcon\Mvc\View;
use \Phalcon\Mvc\Dispatcher;
use \Phalcon\Events\Manager     as EventManager;
use \Phalcon\Assets\Manager       as Assets;
use \Phalcon\Mvc\Url        as UrlProvider;
use \Phalcon\Db\Adapter\Pdo\Mysql   as DbAdapter;
use \Phalcon\Flash\Session      as FlashSession;
use \Phalcon\Session\Adapter\Files  as SessionAdapter;
use \Phalcon\Http\Response\Cookies; 

//use \Phalcon\Session\Adapter\Files  as Session;

class MyApplication extends Application
{

  const DEFAULT_MODULE = "property";
  private $prConfig;
  /**
   * Register the services here to make them general or register in the ModuleDefinition to make them module-specific
   */

  protected function _registerServices()
  {
    try{
      $config = include  "../apps/config/config.php";

      $di = new FactoryDefault();

      $loader = new Loader();

      /**
       * We're a registering a set of directories taken from the configuration file
       */
      $loader->registerDirs(
        array(
          __DIR__ . '/../apps/library/',
          __DIR__ . '/../apps/plugins/'
        )
      );

      $loader->registerNamespaces(array(
        'RealEstate\Common\Plugins' => '../apps/plugins/',
        'RealEstate\Common\Models' => '../apps/common/models/',
        'RealEstate\Library\Pagination' => '../apps/library/',
        'Facebook' =>  __DIR__.'/../apps/plugins/FacebookSDK/'
      ));

      $loader->registerClasses(array(
         "FacebookLib"   =>  __DIR__.'/../apps/library/FacebookLib.php',
         "Facebook" =>  __DIR__.'/../apps/plugins/FacebookSDK/autoload.php',
         "MobileDetect" => __DIR__.'/../apps/library/MobileDetect.php'
      ));

      $loader->register();

      $di->set('config', $config, true);

      //Register assets like CSS and JS
      //ASSETS REGISTRATION RELATED CODE COMES HERE

      $this->prConfig = $config;

      //register base url
      $di->set('baseurl', function() use ($config){
        $url = $config->application->baseUri;
        return $url;
      });

      //register CDN url

      //Module Information
      $di->set('appconfig', function() use ($config){
        $appconfig = $config->application;
        return $appconfig;
      });

      //Register URL helper
      //set base url
      $di->set('url', function() use ($config){
        $url = new UrlProvider();
        $url->setBaseUri($config->application->baseUri);
        return $url;
      });

      //Register dependency for a database connection
      $di->setShared('db', function() use ($config){
        return new DbAdapter(array(
          "host" => $config->database->host,
          "username" => $config->database->username,
          "password" => $config->database->password,
          "dbname" => $config->database->dbname
        ));
      });

      //Register and start session
      $di->setShared('session', function() {
          $session = new SessionAdapter();
          $session->start();
          return $session;
      });

      //Register custom library Utilities, so that it is available through out the application  
      $di->setShared("utils",function(){
        return new \Utilities();
      });

      //Registering a router
      $di->set('router', function() use ($config){

        $router = new Router(false);

        $controller = "index";
        /*Backend Routers Configuration Start*/

        $modules = $config->modules;

        $router->add('/', array(
            'module' => 'property',
            'namespace' => 'RealEstate\Property\Controllers\\',
            'controller' => 'index',
            'action' => 'index'
        ));

        $router->add('/:int', array(
            'module' => 'property',
            'namespace' => 'RealEstate\Property\Controllers\\',
            'controller' => 'index',
            'action' => 'index',
            'params' =>1
        ));

        //other router settings
        //404 route settings here

        $router->removeExtraSlashes(true); //ignore trailing slash in urls
        /*Backend Routers Configuration End*/
        return $router;

      });

     //partials related setting here

      $this->setDI($di);
    }catch(\Phalcon\Exception $e){
      echo get_class($e), ": ", $e->getMessage(), "\n";
        echo " File=", $e->getFile(), "\n";
        echo " Line=", $e->getLine(), "\n";
        echo $e->getTraceAsString();
    }

  }

  public function main()
  {

    try{
      if (!extension_loaded('phalcon')) {
            die("Phalcon extension is not installed or enabled. Please check with host");
      }

      $this->_registerServices();

      if($this->prConfig->application->environment=="development" || $_GET["showerrors"]==1){
        ini_set("display_errors","On");
        error_reporting(E_ALL ^ E_NOTICE);
      }

      $arraytemp = json_decode(json_encode($this->prConfig->modules), true); //convert Config object to a simple array
      //$this->utils->printr($arraytemp,1);
      $keys = array_keys($arraytemp);
      $array = array();

      if(count($keys)>0){
        foreach($keys as $module){
          $array[$module]["className"] = "RealEstate\\".ucwords($module)."\Module";
          $array[$module]["path"] = "../apps/modules/".$module."/Module.php";
        }
      }else{
        die("The entries for modules not found.");
      }

      $this->registerModules($array);
      echo $this->handle()->getContent();

    }catch(\Phalcon\Exception $e){
      echo get_class($e), ": ", $e->getMessage(), "\n";
        echo " File=", $e->getFile(), "\n";
        echo " Line=", $e->getLine(), "\n";
        echo $e->getTraceAsString();
    }
  }

}

$application = new MyApplication();
$application->main();

1. No errors on Server's error log
2. Also have checked on Phalcon 3 on PHP 5.6. Same result

Thanks