First of all, "extrañado" is definitely not a typo; there are quite a lot of examples of the word used in this way in Bolivian legal documents. Maybe "el" is, since "extrañado" is certainly an adjective, and it's much more common to find "lo extrañado", but it could be that "el extrañado" refers to something mentioned previously and is an ellipsis for "el documento extrañado", or something like that.

Anyway, I have not managed to find a definition. My proposal is based on what can be deduced from how the word is used in documents, added to a point already mentioned in the discussion: "extrañar" can mean "to miss": "extrañar a alguien" means to miss someone. Miss in the sense of feel the lack of. So it doesn't seem too implausible that "lo extrañado" means something that is missed, something of which the lack is felt: an omission.

It certainly could be an omission, a document that should have been presented and was not presented, a step that should have been taken and was not taken. But I suspect that it may be slightly broader than that sometimes, and given that it may embrace things improperly done as well as not done at all, it might be better to use "defect" rather than "omission". So here you could say: "The omission have been remedied" or "The defect having been remedied".

Some examples that clearly point in this direction, in my opinion. In this first one it must mean missing documents, required documents that were not submitted:

"Artículo 119º. (FALTA DE REQUISITOS) La autoridad administrativa, si el escrito de presentación no reúne requisitos formales esenciales, podrá requerir al interesado que subsane las deficiencias observadas o acompañe los documentos extrañados, dentro de los cinco (5) días siguientes a su notificación [...]"
http://www.anh.gob.bo/g.php?myfile=Actividad/Dj/RA-2014/RA-0... (p. 1 near foot)

Here it clearly means steps not taken, omissions:

"Si en la acusación el fiscal NO ha cumplido con todos los requisitos el Juez o Presidente dispondrá que el fiscal cumpla con lo extrañado, en cuyo caso se suspende el término de 48 horas. Correspondiendo al Fiscal cumplir con lo extrañado por la autoridad jurisdiccional competente y en el plazo que se le asigne."
http://www.procedimientopenal.com.bo/coment-casos-practicos/...

"I.2. Ausencia de requisitos formales de admisibilidad
En el caso de análisis [...] se advierte la falta de personería [...] por consiguiente, ante dicha omisión, la parte recurrente deberá subsanar lo extrañado y remitir a este Tribunal en el plazo de cinco días"
http://www.tcpbolivia.bo/tcp/sites/default/files/images/apec... (p. 143)

"presentó memorial a través del cual acompañó el documento extrañado por el ente regulador y manifestó lo siguiente (fojas 19)"
https://www.oopp.gob.bo/uploads/R.M._151-2015.pdf (p. 2, 2nd paragraph)

This last one is interesting, I think, because clearly the document was missing and has now been presented, but although it was omitted by the applicant it was "extrañado por el ente regulador", so it seems that "extrañar" means not literally "omit" but rather "feel the lack of", in the sense that the regulatory body noticed and drew attention to the lack of the document. And actually "lo extrañado por la autoridad jurisdiccional competente" points to the same conclusion: the autoridad is the judge, by whom the omission was "extrañado".

Anyway, I've asked my Bolivian neighbour and she doesn't know what it means; it's clearly lawyer-speak. But her nephew is a lawyer in Bolivia and she's sent him a whatsapp. So if I hear anything I'll pass it on.

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Note added at 7 hrs (2017-01-27 10:06:25 GMT)
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Typo near the end of my paragraph 3 above: I meant "The omission having been remedied", not "have been remedied".

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Note added at 15 hrs (2017-01-27 17:41:52 GMT)
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As explained in my further discussion entries, I have consulted a Bolivian lawyer through a contact and have been told that this is a routine type of phrase in a divorce case and simply means that the documents the parties were required to submit were duly submitted. It doesn't actually imply an omission in this case; it simply means "the requirements having been met".

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Note added at 7 days (2017-02-03 19:46:24 GMT) Post-grading
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Thank you, Douglas. As I say, I came to the same conclusion, at least in this particular case: simply "requirement".