Require invitations for new user registrations

Retitling into a feature request. I suspect there's a selection of contrib modules that would provide some or all of this functionality, but I'm not aware of specific ones that will do this out of the box.

http://drupal.org/project/invite

Registration invite
Unfortunately this module has dependency on invite module, and invite module itself isn't working.it seems that this invite module is abandoned. no progress since Oct 2013
Commons should have this feature commons could adopt invite module and incorporate as contrib module

I confirm troubles with invite and Commons.
With Commons, I'm trying to set mail invitations to the site as a whole or to groups.
I intalled https://www.drupal.org/project/invite version 7.x-4.0-beta2 and I allowed users to use it.
invite, invite by email and invite notifications modules are activated.

In the future, I consider other modules to improve my site :
https://www.drupal.org/project/invite_link
https://www.drupal.org/project/userpoints_invite
https://www.drupal.org/project/userpoints_modr
https://www.drupal.org/project/modr8
https://www.drupal.org/project/userpoints_top_contributors

But today it doesn't work completely.
I expected an "Invite" block somewhere, like a "Create a group" button, but it works differently.
As administrator, find the page you want to include an invite block. Click "Customize this page". In the desired zone, click "Add new pane" , then "Miscellaneaous" and "Create invite Invite by e-mail."
Click "Save".
Another question remains : how to display the title in the same color as other titles ?

As I invited a friend by email from my Android phone , I had the following error :
Notice: Undefined property: Invite::$resent ininvite_by_email_send_invitation() (line 347 of /home/patrick/art4/sites/all/modules/invite/modules/invite_by_email/invite_by_email.module).
The problem doesn't show when I invite from a PC.