jfbc invite doesnt open a frame with friends

Marta,
The JFBCInvite module is obsolete and was removed from the 4.1 version and all subsequent releases of JFBConnect. You should upgrade to using the Requests system that is part of JFBConnect from version 4.1+.

The reason it was removed is because the Request system offers huge improvements, including tracking, to the invitation system. Additionally, in December 2011, Facebook announced that the invitation system the JFBCInvite uses would be functionally removed in June. I'm not sure the exact date, but it's possible it recently happened and the JFBCInvite module simply won't work anymore.

Hope that helps explain,
Alex

Marta,
Please make sure you've followed all the steps of the Requests Configuration Guide. There's a lot to getting Requests setup, including an SSL certificate for your site and having the Canvas area fully setup on your site:
www.sourcecoast.com/jfbconnect/docs/facebook-requests

Please let us know if that's all setup, what your Canvas URL is (like apps.facebook.com/your-url), and what page we can test sending the request from and we'll look into it further.

Thanks,
Alex