For those who still has this problem, use this to know the php error you have in your application.
error_reporting(E_ALL); ini_set('error_reporting', E_ALL); ini_set("display_errors", 1);
From there, you can know the exact problem you have.
In my case I had this one
Call to undefined function Illuminate\Foundation\Bootstrap\mb_internal_encoding()
which brought me to conclusion that my server didn't have Mbstring PHP Extension installed (One of Laravel's server requirement). I enabled the extension, and voila, it's working now :)