Pope Pius XI, Divini Illius Magistri (#18), Dec. 31, 1929: “… God Himself made the Church a sharer in the divine magisterium and by His divine benefit unable to be mistaken.” ... “To this magisterium Christ the Lord imparted immunity from error...”

Pope Gregory XVI, Commissum Divinitus (# 4), May 17, 1835: “... the Church has, by its divine institution, the power of the magisterium to teach and define matters of faith and morals and to interpret the Holy Scriptures without danger of error.”

Pope Leo XIII, Caritatis Studium (#6) July 25, 1898: The Magisterium “could by no means commit itself to erroneous teaching.”

Do you realize what these words mean when you hold the exact opposite?

I'm not the one who holds the exact opposite, I accept, echo and hold that their explanations are as true today as they were then and always will be. Until you understand it as the popes have explained it, you will have to really need to admit that their teachings on what the magisterium is are wrong (error), mistaken and erroneous - which actually *is* the exact opposite of what they teach.

For the OP, the Church's universal magisterium is "all that has been handed down as divinely revealed by the ordinary teaching authority of the entire Church spread over the whole world, and which, for this reason, Catholic theologians, with a universal and constant consent, regard as being of the faith." - Pope Pius IX

It is necessary to remember that within the Church, the word "Universal" *always* includes the element of time, as in "since the time of the Apostles and till the end of time," iow, what the Church has taught and the faithful have believed always and everywhere, this is the simple definition of Church's universal magisterium.

It’s really really hard to believe that Stubborn can’t see his contradiction.

Can't vote.  OUM is infallible on matters that are taught thereby to be "divinely revealed" (as per the VI definition).  But, as CE states, as a matter of practical judgment, it's not always possible to discern whether something has been taught infallibly by the OUM.

https://www.newadvent.org/cathen/07790a.htm

Quote

And while for subsequent ages down to our own day it continues to be theoretically true that the Church may, by the exercise of this ordinary teaching authority arrive at a final and infallible decision regarding doctrinal questions, it is true at the same time that in practice it may be impossible to prove conclusively that such unanimity as may exist has a strictly definitive value in any particular case, unless it has been embodied in a decree of an ecuмenical council, or in the ex cathedra teaching of the pope, or, at least, in some definite formula such as the Athanasian Creed. Hence, for practical purposes and in so far as the special question of infallibility is concerned, we may neglect the so called magisterium ordinarium ("ordinary magisterium") and confine our attention to ecuмenical councils and the pope.

Vatican II was an ecuмenical council approved by the pope.  But it had errors in its decrees.  Either the OUM is in error at Vatican II or the man who approved the errors wasn't pope.