What about them 7 Catholic churches mentioned by the angel to John in the first 3 chapters of Revelation?
They are DOCUMENTED as 'teaching error'.
Does the record show that they EVER straightened up and taught what the ECFs considered to be CORRECT?
Their disparity, and utter absence of any mention of a pope, Mary and the Eucharist is contrary to R Catholicism, but these 7 churches of Rv. 2+3 were not all said to be teaching doctrinal error.
The sin of Ephesus was one of the heart, leaving their first love while being diligent in deeds. The church in Smyrna saw no reproofs, only commendations, while the church in Pergamos was guilty of having some that hold the doctrine of Balaam, as well as the doctrine of the Nicolaitans.
The industrious church in Thyatira had this against them, that they suffered that woman Jezebel, which calleth herself a prophetess, to teach and to seduce believers to commit fornication, and to eat things sacrificed unto idols, seemingly part of "the depths of Satan."
The external showy church in Sardis had this against them, that they had a name that they lived but were overall dead, falling short in their works/fruit before God, and only had a few even in Sardis which had not defiled their garments.
The afflicted but preserving church in Philadelphia only saw commendations and exhortations, in stark contrast to the lukewarm church of the Laodiceans , which thought of themselves as being in need of nothing, and knew not that they were wretched, and miserable, and poor, and blind, and naked.
But even the last was not guilty of all the inventions of Catholicism, as well as its overall liberalism .