@prikid: the file is includes/extend/buddypress/group.php in your bbPress plugin directory.
The BuddyPress team did an extensive rewrite of BP_Group_Extension… That’s why it’s breaking like this.
Reverting to the previous version of the groups folder in your BuddyPress installation ain’t even close to a permanent fix, and will cause other issues down the road.
We managed to fix it by changing a few lines in /includes/extend/buddypress: http://pastebin.com/nfYvigz4 (look for “Fix for BP 1.8”, lines 459 and 489)
Not a permanent fix either, but at least it’s a starting point!
Same problem here! Happens both without any additional plugin and with BuddyPress Docs enabled.
