Replace lines 35-36 with:
$kfm_userfiles_address = '../../uploads/';
if (isset($_SESSION['useOverrideRoot'])) {
$kfm_userfiles_address = abs2rel($_SESSION['useOverrideRoot'],dirname(__FILE__));
}
$kfm_userfiles_output = rel2abs($kfm_userfiles_address,dirname(__FILE__));