BuddyPress.org

@dwdutch

@hnla

is_site_admin() is a buddypress function (defined in bp-core-wpabstraction.php) that is being called by Group Documents. This will throw an error if group documents remains activated after you de-activate Buddypress. Although this error will be fixed in the next version of Group Docs, in general, you should deactivate Buddypress plugins before deactivating Buddypress itself