When you try to buy a ticket for a train with compulsory reservation for a date far in the future the SBB website often throws a very unhelpful error message that suggests that the train is in fact sold out, whereas of course that is not the case.
It is just that the system is unable to distinguish between the case “reservations sold out” and “reservations not available yet”. Is the team responsible for the booking site aware of this, and if so are they planning to fix this?