Understanding what 'invincible ignorance' is and how it relates to the Catholic Church's pastoral approach to pedophilia, will help the laity finally understand what goes on in the minds of these Bishops that cover-up the objectively grave sins of their priests when moving them to new parishes where the public does not know of their pedophilia actions. It is precisely because of the 'invincible ignorance' of the pedophile if in not knowing that he commits objectively grave sin when he has sex with your child, produces the circumstance for a Bishop to maintain that since the pedophile's subjective culpability is diminished if not entirely removed by 'invincible ignorance, it can be concluded that the subjective culpability of the Bishop that coverups up the objectively grave sin of the pedophile, is diminished if not entirely removed.
This arrises from a pastoral approach that ignores to inform those entrusted to their care, certain nuances or difference between subjective culpability of a sin and the objective culpability of a sin, so that it arrises that one can teach those entrusted to their care, albeit in an equivocal/ambiguous way, that a sin is not a sin, and what's not a sin is a sin.
So here we have my interpretation of what Pope Francis means to say when he says, that it is because of lack of catechesis that this coverup of pedophilia continues. But what is not considered is that although the Bishops may not be culpable for the pedophile priests' evil actions, the Bishops are still responsible according to the Principle of Double-Effect, that is, by their power and authority to take action that will reduce the bad consequences. The Bishops have a duty to try to mitigate the bad consequences as much as they can so that it can be said that the bad consequence of their pastoral approach were unintentional, that is, so that it cannot be said that the bad consequences caused the good consequences. In other words, the Bishop needs to take into account the objective evil of pedophile victims who commit suicide, the objective evils of allowing the pedophile to remain in situations that are of occasions to sin, the possibility that victims by being taught by the actions of pedophiles that evil is good and good is evil may indeed become murderers. So St.Alphonsus' pastoral approach must take into account the salvation of the souls of the pedophiles' victims as well, who by their actions implicitly teach the victims to have an inverted idea of morality.