When I was able to get your page working, it was using a completely stripped version:
html:
<?php
error_reporting(E_ALL);
ini_set("display_errors", 1);
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
</head>
<body>
<?php
$pg_id = '3';
$pg_theme = 'dark';
include('/home/content/g/s/b/gsbadmin1/html/PowerGallery100/galleries/ribbon_fullsize/index.php');
?>
</body>
</html>
