[Plugin: Secure Invites]Whitescreen on "settings," "bulk invite" "special u

Hi. As of about a month ago, the plugin was working just fine. Since then, I think I updated it with the latest version and now I am unable to use it. I see the Secure Invites Admin page, but when I click on the Settings, Bulk Invites or Special Users links, I get a white screen.

I checked my script logs and it says, (just in case, ‘backticks’) “WordPress database error Invalid use of group function for query select count(u.ID) as signups,
m.meta_value as code
from wp_users u
inner join wp_usermeta m on m.user_id = u.ID and m.meta_key = ‘secure_invite_invitation_code’
group by m.meta_value
order by count(u.ID) desc; made by require_once, do_action, call_user_func_array, secure_invite_list, secure_invite_list_page, secure_invite_signups_by_code, secure_inviters_get_signups_by_code” (‘backticks’)

Anything you can do to help will be greatly appreciated. (We’re ready to launch and don’t know what to do.) Thank you!