Update your server. If that does not help: No way to fix it except for reworking the visibility check in your server.
Aparently, this is an open issue in the bugtracker of trinity.
Quote from: "larrylaffer"Aparently, this is an open issue in the bugtracker of trinity.You answered the question whether this is a issue for everyone yourself.To fix it, fix the bug described in the ticket or wait for someone else to do that.