[otrs] and now an error ..

Hi Martin, how do I get rid of this error or better how do I get rid of the ticket associated with that one ? Error: No customer article found!! (TicketID=20) Comment: Please contact your admin Bug Report: Click here to report a bug! Handle: /opt/OpenTRS/bin/cgi-bin/index.pl Frontend Subfunction: Kernel::Modules::AgentQueueView::ShowTicket (v 1.18) Frontend Line: 311 Backend Subfunction: (v ) Backend Line: Backend BackendMessage: