I’m having issues with settin up a forum either.
Set up WordPress, installed Buddypress and first tried to get sitewide forums running. Kept getting the complaint that the forums component wasn’t set up yet, although I was quite sure it was.
Then de-installed bbpress and set up a groups forum.
I have a forum directory now, but when I want to create a new topic it says: please pick the group forum where you would like to post this topic. Although I just did in the little dropdown menu below.
I really, really would like to hav a step by step tutorial on how to set up a forum in buddypress, with a private community. One that fits the screens I see, because most blogs and tutorials about this look older and have losts of different screens and features.