should be build_sort_order_category - sorry - thought I'd checked this.
If you use this:
$link_db->select_options ("ORDER BY $CFG->{build_sort_order_category}") if ($CFG->{build_sort_order_category});
you shouldn't get the error message even if it doesn't work.
If you use this:
$link_db->select_options ("ORDER BY $CFG->{build_sort_order_category}") if ($CFG->{build_sort_order_category});
you shouldn't get the error message even if it doesn't work.