BuddyPress.org

I’m using the twentyfourteen theme with bbpress 2.5.4 forums as part of Buddypress 2.1 on WordPress 4.0.

When I try to create a new topic in a forum, I get a black page with the following in the tab:

<br/> <b>fatal error</b> Call to undefined function: bb_get_id_from_slug() in <b> (…)bp-forums-functions.php <b/> on line <b>265</b>

One of the forums is here: http://www.southernperspectives.net/groups/lab-group/forum/

Any suggestions to resolve this would be much appreciated.