Blank login? Tip: Don't forget to re-comment config.php

Don't forget that you need to re-comment

    $security_headings = array(
            _("Inquiries"),
            _("Accountant"),
            _("System Administrator"),
    );

    $security_groups = array(
            array(1,2),
            array(1,2,3,4,5,6,7,8,9,10,11,12,13,14,16),
            array(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,20),
    );

After your install, or you may see a blank screen when you login.
This is in the instructions somewhere, but had me stuck for a few minutes!