CMS install on IIS problem

I’ve followed all manual installation steps on server 2012, but when I navigate to localhost/xibo I get a blank page. If I make the default document a php doc that echos the version that works, and html docs work. But the index.php does nothing.

I assume you’re referencing this guide? XIBO step by step Installation IIS 8.5 on WINDOWS SERVER 2012

If you open a dev console in your browser on your CMS url does it show any specific errors there?

Yes I am.

It just shows error 500 on chrome. IE is a blank page when I turn off friendly http errors. IE gave me a 1527 doctype expected. So I added HTML tags around the entire doc, but that only made the error go away. Now IE just says HTML1300: Navigation occurred.

Now index.php looks like this:

<!DOCTYPE HTML>
<html>
<?php
rest of code here
    ?>
</html>