You may encounter an Error 403 with Simple Hosting instances in the following event:
[Mon Nov 25 09:33:29.272185 2013] [autoindex:error] [pid 2502:tid 2981512099584] [client 2001:4b98:x:x:x] AH01276: Cannot serve directory /srv/data/web/vhosts/domain.example.com/htdocs/: No matching DirectoryIndex (index.php,index.html,index.htm) found, and server-generated directory index forbidden by Options directive
By default, the Apache web server delivers the page named 'index.html' or 'index.php' at the root of the directory, as the homepage. Consequently, if you encounter this error, you need to rename the homepage of your website to be 'index.html' or 'index.php'. If you do not want to modify the name of the file of your homepage, you can also add the directive ' DirectoryIndex' in a '.htaccess' file located at the root location.