No, it's something in the tree xml.
on a couple of rare occasions i have seen issues where the common logic of the file structure doesnt quite work as expected.
Usually ,the require path is relative to the file the connection being added to, but in a couple of cases, i have seen where the require path is relative to the page the menu is in instead.
try changing:
<?php
// MenuWriter connection includes
require_once("../../Connections/PowerStoreConnection.php");
to:
<?php
// MenuWriter connection includes
require_once("Connections/PowerStoreConnection.php");