.htaccess - What's wrong with this htaccess file

Question

I'm trying to use this .htaccess file in an mvc project to redirect everything to the index page/controller/method/params but when I go to the root directory I get a 500 error. Is there something wrong with the code:

php_flag display_errors on
php_value error_reporting 9999

RewriteEngine On
RewriteBase /mvc/

RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-l

RewriteRule ^(.+)$ index.php?url=$1 [QSA,L]