by virtue of the error [***in the proceedings***], no party can prevail ...

You mentioned it was a divorce case, but there is insufficient context to determine what type of error was committed, **whether procedural, or other**. The Judge is, therefore, obliged to make good (to correct) this.

subsanar vt
[+falta] to overlook, excuse
** [+perjuicio, defecto] to repair, make good **
[+error] to rectify, put right
[+deficiencia] to make up for
[+dificultad, obstáculo] to get round, overcome

https://livinglies.wordpress.com/tag/credit-bid/
The creditor now prevented from seizing the collateral ***by virtue of the error of the trial court***, sues the borrower for the money due.

I think? HTH.

--------------------------------------------------
Note added at 6 hrs (2015-10-05 20:02:34 GMT)
--------------------------------------------------

To Álvaro:

I agree that "prevalerse" means: "to take advantage of"
http://www.oxforddictionaries.com/translate/spanish-english/...
prevalerse de algo
to take advantage of something
avail oneself of something [formal]
prevalerse de sus amistades/su inmunidad diplomática SP. LAT. AM. SP.
to take advantage of o to use one's friendships/diplomatic immunity
prevalerse de sus influencias SP. LAT. AM. SP.
to use one's influence

However, the fact remains, IMO, it is still unclear, i.e. "de el"?, and whether there is something missing which was a point raised by another peer, and there is insufficient context to determine with accuracy, as the type of "error" is not stated. Regards.