内部服务器错误修剪和.htaccess

Question

First I need to say ya sorry for my bad english I hope u can help me strangers. I have created a domian in my linux Debian 8. look it

<VirtualHost *:80>

ServerAdmin [e-mail]  
DocumentRoot "/var/www/saci"
ServerName saci.com
ServerAlias www.saci.com

ErrorLog ${APACHE_LOG_DIR}/error.log
CustomLog ${APACHE_LOG_DIR}/access.log combined


<Directory "/var/www/saci">
    Options Indexes FollowSymLinks MultiViews
    AllowOverride All
    Order allow,deny
    Allow from all
</Directory>
</VirtualHost>

I'm using slim and I've created a folder named 'app' on the folder 'saci' with a file start.php that got this:

<?php

use Slim\App;

session_cache_limiter(false);
session_start();

ini_set('display_errors', 'On');

define('INC_ROOT', dirname(__DIR__));

require INC_ROOT . '/vendor/autoload.php';

$app = new App();

$app->get('/test', function() {
echo "this is a test.";
});

?>

Now on my folder saci I've created a folder named Public with one index.php and one .htaccess. so now look my roots

Var > www > saci > public

index.php <------------------index daaa

.htaccess <------------------.htaccess

var > www > saci > app

start.php <----------------start

so now my problem is here I've got an index.php with this

<?php
require '../app/start.php';
$app->run();

and a .htaccess with this

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^ index.php [QSA,L]

but when I go to my host www.saci.com I can see my index of/ with all my proyects folders But I cannot see the folder public, and if I go to www.saci.com/public

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator at [e-mail] to inform them of the time this error occurred, and the actions you performed just before this error.

More information about this error may be available in the server error log.

Apache/2.4.10 (Debian) Server at www.saci.com Port 80

I rly DON'T HAVE IDEA of what is going wrong I need rly rly help

starting now

Thanks Steangers U rock never forget smile

Greetings from Venezuela