"Invite to Group" button does nothing

[JoeyGiuf]

Summary:
Clicking the "Invite to Group" button does nothing.

Description:
While on another user's profile, there is an "Invite to Group" button that is shown. When clicking this button, there is nothing that happens. If an invite was actually sent, there should be confirmation to the user indicating this.

Severity:
Blocker - this seems to be crucial for the application to be fully functional.