Re-setting up working project on local machine

Question

I'm working on a symfony 1.4 project which is working, i wanted to work on a local copy on my personal machine; so I've settled a virtual host (I'm on a Windows 8.1 with xamppp web server). I'm getting a 500 error when trying to access from browser by giving "joyaa" (it's the virtualhost alias), and in some of my test I had a redirect to the project working on the server (it's a statement in .htaccess)

This is the virtual host defining:

<VirtualHost *:80>
ServerName joyaa
DocumentRoot "C:/xampp/htdocs/yaol/web"
DirectoryIndex index.php
<Directory "C:/xampp/htdocs/yaol/web">
    AllowOverride All
    Allow from All
</Directory>

Alias /sf C:/xampp/htdocs/yaol/lib/vendor/symfony/data/web/sf
<Directory "C:/xampp/htdocs/yaol/lib/vendor/symfony/data/web/sf">
    AllowOverride All
    Allow from All
</Directory>

Alias /joyaa "C:/xampp/htdocs/yaol/web"

<Directory "C:/xampp/htdocs/yaol/">
    Options Indexes FollowSymLinks
    AllowOverride All
    Order allow,deny
    Allow from all
</Directory>

</VirtualHost>

and this is the .htaccess defining:

Options +FollowSymLinks +ExecCGI
<IfModule mod_rewrite.c>
  RewriteEngine On
  RewriteBase /joyaa
  RewriteRule ^yaol(.*)$ http://www.arcadja.com/joyaa$1 [L,R=301]
  # we check if the .html version is here (caching)
  RewriteRule ^$ index.html [QSA]
  RewriteRule ^([^.]+)$ $1.html [QSA]
  RewriteCond %{REQUEST_FILENAME} !-f

  # no, so we redirect to our front web controller
  RewriteRule ^(.*)$ index.php [QSA,L]

</IfModule>

Probably it's a configuration problem but I'm not sure about where to look at... Please help. Thanks