Like the list in Protestant errors, not everyone will agree on these. Feel free to suggest others. #27 is added from a suggestion.
1) Eucharist Adoration (the worship of the bread, rather than God).
2) Accepting bad theology from those who contradict scripture (devotions to "sacred" hearts, worship of angels).
3) Accepting "regenerative" baptisms of heretical groups as on par with Christian baptism.
4) Maintaining the clergy/laity split, rather than promoting the biblical priesthood of believers.
5) Believing Christ died on Good Friday.
6) Believing Christ rose in the night or at sunrise Easter Sunday.
7) Maintaining more than 66 books of the bible as inspired (God breathed).
8) Believing there is salvific information necessary for Christians apart from the bible.
9) Maintaining that Jesus Christ was not born in the normal human way (with afterbirth), thus ending virginity. Subsequently there was the substituting of Mary as the Great Goddess myth of Artemis/Diana.
10) Believing there is another way to God besides Christ (the Roman Church sums up this belief Those who, through no fault of their own, do not know the Gospel of Christ or his Church, but who nevertheless seek God with a sincere heart, and, moved by grace, try in their actions to do his will as they know it through the dictates of their consciencethose too may achieve eternal salvation.) .
11) Ignoring tradition that ties directly to scripture.
12) Defining "apostolic succession" as anything other than "teach the same" as apostles.
13) Believing Peter assigned anyone at Rome his authority (1 Peter 5:1-3 Peter calls the elders of Asia Minor and gives them the same authority (feed His sheep)).
14) Assumption of Mary as a salvific belief.
15) Immaculate conception as a salvific belief.
16) Sacerdotal sacrament.
17) Works necessary to maintain salvation.
18) Submission to the Roman Churchs Pope as salvific (unam sanctam and lumen gentium, confirming same doctrine)
19) Purgatory.
20) Transubstantian.
21) Ignoring Council decisions.
22) Failing to discern the Body of the Lord, calling them communities, rather than churches (or The Church).
23) Infallibility.
24) Failing to understand the Roman Church is a denomination.
25) The Roman Church pretends the authority of apostles (Firmilian 256ad).
26) RC believes neither EO, OO, Anglican, Baptist, Lutheran, etc can interpret the Word of God (bible/tradition).
The task of interpreting the Word of God authentically has been entrusted solely to the Magisterium of the Church, that is, to the Pope and to the bishops in communion with him.
27) Praying to the dead, even though scripture forbids it.
28) Reserved