Ethan’s Photo Upload hack/rewrite (please help!)

If any of you have used this, could you please help me with a problem I’m having? (Ethan says he doesn’t currently have time to look at the hack/rewrite.)
The hack’s/rewrite’s URL: https://www.ethan.speakings.net/index.php?p=27
My problem: If I go into the plugins menu and hit “activate” for his hello.php, it says it activates it, but when I try to go into any other menu, it loads a blank page, making it so I can no longer use any menus after I activate it. (!) The hello.php code is as follows:
<?php
/*
Plugin Name: photo upload
Plugin URI: https://www.ads-software.com/#
Description: this puts a file upload button on the quick tags bar.
Author: Ethan King
Author URI: https://www.ethan.speakings.net/index.php?p=27
*/
// We need some CSS to position the paragraph
function launch_pu() {
echo "
<script type='text/javascript' language='javascript'>
<!--
function launchupload() {
window.open ('/family/pu-upload.php', 'wpupload', 'width=380,height=360,location=0,menubar=0,resizable=1,scrollbars=yes,status=1,toolbar=0');
}
//-->
</script>
";
}
add_action('admin_head', 'launch_pu');
?>
Does that look okay? If so, it must be a problem with one of the other files, so I’m really hoping it’s a problem with this one. =(
I would appreciate any help. TiA!