In line 9 of the last version of upload.php is a wrong include path:

<?php require_once('/ScriptLibrary/incPureUpload.php'); ?>

This cannot work, require and include uses the server path, not the browse path.

Right would be a relative path:

require_once('../../incPureUpload.php');

or a constant for the html server root, which must be previously defined, for example, BASEPATH:

require_once(BASEPATH.'/ScriptLibrary/incPureUpload.php');