just to let you know...
My config: local install, WordPress 4.4.2 - BuddyPress 2.5.0 - bbPress 2.5.8 and Graphene 18.104.22.168
when bbPress search widget is active, the search result page throws a php notice:
Trying to get property of non-object in ...wp-content\themes\graphene\loop-page.php on line 44
The template file is trying to get the post "edit" link here, which is not appropriate on a result page.
A possible workaround would be to add an additionnal conditionnal to the if statement line 42 (in the child-theme in my case).
if ( is_user_logged_in() by
if ( is_user_logged_in() && !class_exists( 'bbPress' ) ) did the trick
The bug related here for Graphene was initially reported on buddypress forum
Thank you for your attention.