BuddyPress.org

Are you using the wpmu 2.7.1 beta and bp trunk? The error leads me to believe one or the other isn’t so. See in here: https://buddypress.org/forums/topic.php?id=2190 there’s a post about getting the most recent bp and wpmu.

You might want to talk to the theme author. Perhaps they have seen this error in relation to the theme before.