At the beginning of each year, Pope John Paul II speaks to the dean, judges, promoters of justice, defenders of the bond, officials and attorneys of the Roman Rota.  The Roman Rota is the court of appeals for Catholic Tribunal courts all over the world.  The pope cautions tribunal judges against presuming a marriage is invalid just because the couple (or one party) failed at keeping their matrimonial promises.

Excerpts from the Pope's statements to the Roman Rota
Jan 29, 2004
          Then what can one say to the argument which holds that the failure of conjugal life implies the invalidity of the marriage? Unfortunately, this erroneous assertion is sometimes so forceful as to become a generalized prejudice that leads people to seek grounds for nullity as a merely formal justification of a pronouncement that is actually based on the empirical factor of matrimonial failure. This unjust formalism of those who are opposed to the traditional favor matrimonii can lead them to forget that, in accordance with human experience marked by sin, a valid marriage can fail because of the spouses' own misuse of freedom.
          Admission of true nullities should rather lead to ascertaining with greater seriousness at the time of the marriage the necessary prerequisites for matrimony, especially those concerning the consent and true disposition of the engaged couple. Parish priests and those who work with them in this area have the grave duty not to surrender to a purely bureaucratic view of the pre-matrimonial examination of the parties, specified in can. 1067. Their pastoral intervention must be dictated by awareness that at precisely that moment, people are able to discover the natural and supernatural good of marriage and consequently commit themselves to pursuing it.". (sec 5)

        The tendency to instrumentally broaden the causes for nullity, losing sight of the bounds of objective truth, involves a structural distortion of the entire process. In this perspective the preliminary investigation would lose its effectiveness since its outcome would be preordained. (sec 6)

The essential dimension of the justness of marriage, which is based on an intrinsically juridical reality, is replaced by empirical viewpoints of a sociological, psychological, etc. kind, as well as by various forms of juridical positivism. (sec 7)