It appears to be a server configuration issue. I added code to the first line of the index.php page:
<?php die("here"); ?>
That should just write "here" to the page and not run any of the code on the page.... since I don't even see that and the page hangs and errors that means it isn't even getting to the page. So it must not be an issue with the powerstore code itself. It is an issue with the server not getting to that page.
I'd contact your hosting provider to get help accessing your site. They should be able to get it resolved.