Please point out for us the passage(s) in Holy Writ teaching the Church Jesus established (matt 16:18,19) would teach error? Scripture teaches the church is the Pillar and Ground of truth; not error.
It defies logic to think Jesus would establish a Church, send the Holy Spirit upon it to teach it all truth but the Triune God would let that Church teach error. But, that is the protestant position as I understand it.
However, I have never seen an opponent of the Church Jesus established use Scriture as evidence Jesus established a Church that, in essence, lies; teaches error; and leads hundreds of millions to Hell.
Please note the churches of Revelation 2-3 (persumably all Catholic Churches). If memory serves me correctly they all except one held some sort of error or failed to deal with a problem. One has to believe the Lord Jesus established those Churches and was quite upset with their teachings and behavior.
BTW-The scripture shows that our Lord Jesus looked at these churches individually-not collectively under some Pope.
Scripture mandates sound doctrine
Titus 1:9 He must hold firm to the trustworthy word as taught, so that he may be able to give instruction in sound doctrine and also to rebuke those who contradict it.
There was a lot of unsound doctrine in the RC church back then, wouldn't you say?