Php – SimpleSamlPHP Apache 403 Client denied by Server

I've set up a PHP Application (SimpleSAMLphp 1.10.0-rc2). After upgrading to Apache/2.4.7 (Ubuntu) I got a 403 Forbidden.

SimpleSAMLphp's www dir is in /var/simplesamlphp-1.10.0-rc2/www

There's a Apache config file which is in apache2/conf.d/simplesamlphp.conf:

Alias /simplesamlphp /var/simplesamlphp-1.10.0-rc2/www

<Directory /var/simplesamlphp-1.10.0-rc2/www>
  Options -Indexes FollowSymLinks
  AllowOverride AuthConfig FileInfo
  Order allow,deny
  Allow from all
</Directory>

It seems that it's not interpretated, because it just gives me a 404. When I add the snippet to apache2/sites-available/000-default.conf it gives me a 403. The logs look like that:

mod_authz_core.c(802): [client xxx] AH01626: authorization result of Require all denied: denied
mod_authz_core.c(802): [client xxx] AH01626: authorization result of <RequireAny>: denied
[client xxx] AH01630: client denied by server configuration: /var/simplesamlphp-1.10.0-rc2/www/

If I set the directive to

<Directory /var/simplesamlphp-1.10.0-rc2/www>
  Require all granted
</Directory>

the logs show me:

AH01797: client denied by server configuration: /var/simplesamlphp-1.10.0-rc2/www/

Files are owned by www-data.

Any suggestions?