Yep, encountering the same Chateau bug.
This is a really ugly hack, but I solved the problem by opening;
.kolmafia/scripts/yaaz/quests/special/yz_chaeatu.ash <== I am a Linux user, if you are using Windows all I can say is it is there somewhere.
and commenting out lines 45-64 as such.
# if (!to_boolean(get_property("_chateauDeskHarvested")))
# {
# log("Collecting items from the " + wrap("Chateau Mantegna", COLOR_LOCATION) + " desk.");
# int desk = 0;
# if (get_chateau() contains $item[swiss piggy bank])
# {
# desk = 1;
# } else if (get_chateau() contains $item[continental juice bar])
# {
# desk = 2;
# } else if (get_chateau() contains $item[fancy stationery set])
# {
# desk = 3;
# }
# if (desk > 0)
# {
# visit_url("place.php?whichplace=chateau&action=chateau_desk" + desk);
# }
# return true;
# }