Реестровую ошибку и наложение границ исправили вчера.

Because they are the direct objects of исправили (corrected/fixed), so they are in the accusative case.

• реестровая ошибка → реестровую ошибку
  • adjective + noun, feminine singular accusative
• наложение границ
  • наложение is neuter singular, and for many neuter nouns the accusative looks the same as the nominative
  • границ is genitive plural after наложение: literally something like overlapping of boundaries

So the sentence structure is basically:

• [They] corrected what?
  • реестровую ошибку
  • и наложение границ

Исправили is past tense plural.

In Russian, a sentence can omit the subject when it is understood or not important. Here, the sentence means something like:

• They corrected the registry error and the boundary overlap yesterday.

This is a very common Russian pattern: third person plural with no stated subject to mean they, someone, the authorities, the workers, the office staff, etc.

So исправили does not agree with ошибку or наложение. It agrees with the implied subject: they.

Russian often leaves out the subject when it is obvious, unknown, or unimportant.

Here, the focus is on the fact that the problem was fixed, not on exactly who fixed it.

So instead of saying:

• Сотрудники исправили...
• Специалисты исправили...
• Они исправили...

Russian simply says:

• Исправили...

This sounds natural and common.

Because the sentence refers to a completed action.

• исправили = they corrected/fixed it successfully; it got done
• исправляли = they were correcting / they used to correct / they worked on correcting

Since вчера (yesterday) usually refers to a finished event, исправили is the natural choice here.

So the sentence emphasizes the result: the error and the overlap were actually fixed yesterday.

It is a noun phrase made of:

• реестровую = adjective, feminine singular accusative
• ошибку = noun, feminine singular accusative

Its dictionary form is:

• реестровая ошибка

Because it is the direct object of исправили, both words change to the accusative:

• реестровая ошибка → реестровую ошибку

This is a standard adjective + noun agreement pattern in Russian.

Only part of it changes visibly—or rather, in this case, it doesn’t need to.

• наложение is a neuter inanimate singular noun
• for that type of noun, nominative and accusative are usually identical

So:

• nominative: наложение
• accusative: наложение

Meanwhile, границ is already in the genitive plural, because наложение is followed by of boundaries:

• наложение чего? → границ

So the phrase already has the form it needs.

Because наложение is a verbal noun meaning something like overlapping/imposition, and it commonly takes another noun in the genitive to show what is overlapping.

So:

• наложение границ = overlap of boundaries

Compare the same pattern in English:

• registration of property
• correction of errors
• overlap of boundaries

In Russian, this noun + genitive structure is very common.

It connects two direct objects:

• реестровую ошибку
• наложение границ

So the meaning is:

• They corrected the registry error and the boundary overlap yesterday.

This is why both object phrases are in the accusative position after the verb.

Yes. Russian word order is flexible, and changing it usually changes the focus rather than the core meaning.

For example:

• Реестровую ошибку и наложение границ исправили вчера.
  • focus can feel like: these issues were fixed yesterday
• Вчера исправили реестровую ошибку и наложение границ.
  • stronger focus on yesterday
• Исправили вчера реестровую ошибку и наложение границ.
  • also possible, though less neutral in some contexts

The original sentence is perfectly natural and puts the two problems near the front.

Putting вчера at the end is a normal way to place the time expression after the main information.

Russian often places time words flexibly:

• Вчера исправили...
• Исправили вчера...
• ...исправили вчера

All are possible.

In this sentence, the end position makes вчера sound like the final time detail: the problems were fixed, and that happened yesterday.

Word-for-word, yes, but in natural English you normally need a subject:

• They corrected the registry error and the boundary overlap yesterday.

Depending on context, English might also say:

• The registry error and the boundary overlap were corrected yesterday.

Russian allows the subject to remain unstated much more easily than English does.

Grammatically, it is active, because the verb is исправили = they corrected.

But in terms of style, it can feel somewhat similar to English sentences where the agent is vague:

• They corrected it yesterday.
• It was corrected yesterday.

Russian often uses this active plural with omitted subject instead of a passive construction.

A more explicitly passive Russian version would be something like:

• Реестровая ошибка и наложение границ были исправлены вчера.

That version sounds more formal and focuses even more on the result than on the people who did it.