If a page displays as blank it usually means that there are errors on the page and php error reporting is turned off. You can enable php error reporting on the index page by putting this code at the top of the page:
<?php
error_reporting(E_ALL);
ini_set('display_errors','on');
?>
This should allow you to see the errors that are occurring. If you have the same result after applying this code to your index page you may need to talk to your host about enabling error reporting in php.