WP 3.6.1, BP 1.8.1,
I think an error notice is produced in a single site buddypress installation and that this MAY be caused by another good buddypress plugin.
Please see image of error notice at http://i.imgur.com/dAvPn6T.png to confirm.
Deactivating this plugin eliminates the error notice.
In any event the plugin works with bp-group-documents active but when bp sticky is changed the error notice appears and then disappears on page refresh.