EDIT

//        getView().openReferenceEditor(null);

//    }

    public void onReferenceEditEvent(ReferenceEvent event) {

        getView().openReferenceEditor(null);

    }

    @EventListener(classes=ShowDetailsEvent.class, condition = "#event.entityType == T(eu.etaxonomy.cdm.vaadin.model.registration.RegistrationWorkingSet)")

    public void onShowRegistrationWorkingSetMessages(ShowDetailsEvent<?,?> event) { // WARNING don't use more specific generic type arguments

        List<String> messages = new ArrayList<>();