[FactQuest]

That still doesn't compute.

Surely, the original error of the previous Pope had to be ex-cathedra as well, right?

Or, do we sweep all errors of Popes into the non-ex-cathedra category? Isn't that too convenient?

If infallibility is limited only to ex-cathedra, then why all the furor over Vatican II? Oh, is it because, ex-cathedra, that Pope changed a lot of things, that had been ex-cathedra before him? And thus, any change corrected an error or introduced an error, and thus, even ex-cathedra, some pope somewhere erred?

[Hermann the Cherusker]

If infallibility is limited only to ex-cathedra, then why all the furor over Vatican II? Oh, is it because, ex-cathedra, that Pope changed a lot of things, that had been ex-cathedra before him?

Vatican II didn't change any teachings of the Church.