Buddypress Message Auto-complete, inclusion of Non-friends

You have to edit the file wp-content/plugins/buddypress/bp-messages/bp-messages-loader.php

on line 92

change

        $this->autocomplete_all = defined( 'BP_MESSAGES_AUTOCOMPLETE_ALL');

to

        $this->autocomplete_all = define( 'BP_MESSAGES_AUTOCOMPLETE_ALL','true' );