This turns out to be a very difficult issue to resolve, and very odd. The problem appears to be that a method which works in Standard (being depot_t *depot_t::find_depot( koord3d start, const obj_t::typ depot_type, const player_t *player, bool forward)) fails in Extended when the last parameter, "forward", is false when the same method, with exactly the same code, works in Standard. This is rather mystifying, I am afraid.