Yes, Feeneyism and R&R have the same root error that the Church can promulgate doctrinal error and be unsafe to follow.

The whole point of the Church is to be a safe guide.

No further debate is necessary really, it's just that simple.

Ridiculous, characterizing the notion that the Church's Magisterium cannot become corrupt as novelty.  We have consistent teaching of the Popes and the Church Fathers, Doctors, theologians, that the Magisterium cannot be stained with error.  Yet no theologian holds that the Magisterium is ABSOULTELY free from error.  So what does it mean for the Magisterium to be free from error and not stained by error?  It means that it's substantially or essentially free from error, even if there can be some error there per accidens.  That's the distinction, and Msgr. Fenton, in the passages cited, articulately expressed the threshold between fallibility and infallibility, which you continue to ignore.

Proposition I:  Magisterium is free from error and all stain of error [taught above by the Popes ... which you reject]
Proposition II:  Magisterium is not absolutely guaranteed to be free from error [taught by all theologians]

So then this apparent contradiction requires a distinction for both of these to be true.  That distinction is substantial vs. accidental, or as Msgr. Fenton characterized it extensive and harmful.

You reject Proposition I above by attributing the doctrinal corruption and the corruption of the Mass to the legitimate authority of the Catholic Church, and that's heresy.  You keep throwing the word novelty out there, but I defy you to find any Catholic theologian ever who agrees with you that the Magisterium can go off the rails so badly that it justifies severing submission to and communion with the Holy See.

THAT is novelty, not my (and Msgr. Fenton's) distinction to reconcile the notion that the Magisterium is inerrant and unstained by error, and yet not absolutely free from error.  This distinction is absolutely common sense.

Maybe you can get it through to his thick skull.

As I said in this thread, there are Sedes who have taken his position regarding indefectibility, who are consistent, and have made a viable case regarding Sedevacantism. For example, in terms of those whose opinion I respect and who are worthy of much consideration, John Daly, John Lane, Bishop Sanborn, Father Cekada . . . those are the ones that jump out to me at the moment.

His position is totally inconsistent, and one cannot regard him seriously. He hurts the Sede position with his contradictions.

This would be laughable if it isn't so tragic.  Here you put your dishonestly on display in glaring fashion.

Those men you cite as "worth of much consideration" would agree with me that your attribution of error to the Church (V2 and the New Mass) is in fact heretical.  I know for a fact that Bishop Sanborn would, as Father Cekada woud have (RIP).  They would condemn your position as heretical even much more strongly than I do, and Servus here has no use for your heresy either.

But YOU disagree with them about infallibility, and yet you would force me to accept their view of infallibility.  This is absurd dishonesty, and you should be embarrassed

I disagree with them regarding the extent and the scope of infallibility.  I believe that they've ended up in this exaggerated position precisely as the result of having to combat heresies such as yours.

But you've played a lot of games to distract from the core issue.  You lump all "Magisterium" in the same category, whereas in fact there are different degrees of authority within the Magisterium.  I've never said that an Ecuмenical Council could teach error in any way shape or form, just lesser expressions of the Magisterium ... a letter by a pope to a bishop, a papal allocation, and to a lesser extent a papal encyclical.  Ecuмenical Councils cannot teach error.  But I hold that Trent did not teach BoD (as you try to define it, and most certainly didn't teach the heretical Pelagian form of BoD that is prevalent out there).  If I believed that Trent actively taught BoD, then I would of course accept it.  But the simple fact is that it did no more than mention a term votum, saying that justification cannot take place without it.

So you keep playing dishonest games like this to justify your false dichotomy that either there can be errors in the Magisterium or there can't be, going so far here as upholding as "worthy of consideration" the dogmatic Sedevacantists who would condemn for heresy even more strongly than I have ... and rightly so.  But then you try to falsely leverage the notion that there can be errors in the Magisterium to assert that the Magisterium (and the Mass) can become so corrupt that it requires severing communion with the Catholic hierarchy.

You keep trying to play games to re-assert your false dichotomy in order to justify your heresy.

Where Daly and co. and Stubborn differ is in their understanding of the Vincentian canon. Daly and co. hold that the universality just has to be spatial: since the current (or recent) popes and the bishops in union with them contradict prior teaching (an inconsistency incompatible with truth), they are not true popes and bishops of the Church.

Stubborn hold that they are true popes, but where there teaching departs from prior teaching, thus being inconsistent with Tradition (lacks temporal universality), it shows that is it not Magisterial teaching.

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The Catholic teaching is that the papacy is the sure rock of Peter on which we must base our faith. This has been taught literally dozens of times by the popes, of which the page I quoted is just a small sample.

The problem with Stubborn's position in the second paragraph quoted (assuming it accurately describes Stubborn's position) is that it means that the pope and all the bishops can lead people astray by teaching what they claim is the Catholic faith, quod absit.

Sorry, I meant this paragraph in which 10 was stating your position:

Stubborn hold that they are true popes, but where there teaching departs from prior teaching, thus being inconsistent with Tradition (lacks temporal universality), it shows that is it not Magisterial teaching.

There is the Sede position of Daly, etc. It is consistent on its own (their own) terms, and it is a viable argument. It says that the Conciliar Church is a false Church and the Conciliar popes are false popes because they and the bishops in union with them teach contra to what the Church has taught in her extraordinary and ordinary universal Magisterium. The Magisterium, to them, consists of whatever the current popes and bishops in union with them say. This is a spatial universality: the pope and all the current bishops united with him throughout the globe (space).