Urgent! Error message when going to INVITE page

"CollectiveX :: 404
That page couldn't be found.. if you came here from another site, check the URL and try again; otherwise, perhaps that item has been deleted?
Use the Back Button on your browser to return to the previous page."

The page works fine for a Manager, but not for other users, no matter what groupsite it is.

ps The timing on this was a little bad because the person who told me this was looking to invite several dozen people all at once this morning after we got the group all excited (in person) the previous night, and he couldn't do it. The invite needs to come from him.