Skim less. Be more aware of confirmation bias.

The children who are born into these Communities and who grow up believing in Christ cannot be accused of the sin involved in the separation, and the Catholic Church embraces upon them as brothers, with respect and affection. For men who believe in Christ and have been truly baptized are in communion with the Catholic Church even though this communion is imperfect. (UR, 3)

Here is one of the supposed "problem areas" that I've been hearing about. True, this particular passage seems to imply that Protestants are not heretics, and are in fact part of the one true Church. The part "are in communion with the Catholic Church..." is of particular interest, although the passage goes on to state that this "...communion is imperfect..." Many Catholics would object to even the mere suggestion that the Protestants are "in communion with the Catholic Church," as Church teaching clearly dictates that they are not, since they teach contrary to Church teaching, or reject aspects of Catholic doctrine or dogma. It may only be one particular point that they reject, but if they reject any of the doctrine or dogma, they are not part of the Catholic Church, and are therefore not in communion with it.

On the flip side, there are also many Catholics who would interpret the above passage as stating that the Protestants are no longer considered outside the Church, even though the qualification "...even though this communion is imperfect," makes it clear that although we may recognize Protestants as validly baptized, they are still not in communion with the church (i.e. imperfect communion as opposed to perfect communion, although the document nowhere defines any of that).

Here's my take, per what's actually written there: those that are born into Protestant sects, and have never been exposed to the fulness of Truth, are only subjected to the heretical teachings of their religious leaders, and therefore do not understand that what they've been taught is heretical or incomplete, as the passage states cannot be truly held responsible for their heresies. Only after they have been evangelized and taught the fulness of Truth do they become responsible for it. To me, this passage does not imply that all Protestants are ipso facto members of the Catholic Church, although you can find people much more qualified than I to discuss such matters that make convincing arguments to that effect.

@Liam: I don't understand your comment. You clearly suspect that I have a bias towards what I concluded, but have not provided your own view on the topic, which is what I explicitly asked of other forum members. It is not entirely possible that your own views on the topic, and my conclusions regarding it are subject to that same confirmation bias?

Interesting, Chonak!
I am among the many who would not have thought such sharings probable.
There is an interesting close parallel with European Protestants. Somewhere just a few months ago I read that in many towns in Europe it was not uncommon for Catholics and Protestants to share the same facilities and buildings. They, of course, had their own separate and distinct worship, but there were, otherwise, quite filial relationships. Distinctly, I remember this source telling about how the Protestants would merely draw a curtain in front of the Catholic altar area and have their own service.