Не вини себя за эту ошибку.

A very literal breakdown is:

• Не = not / don't
• вини = blame (imperative, singular: blame! / with не → don't blame)
• себя = yourself
• за эту ошибку = for this mistake

So the sentence is literally:

Don't blame yourself for this mistake.

Вини is the singular informal imperative of the verb винить (to blame).

So:

• винить = to blame
• вини! = blame! (to one person, informal)
• не вини! = don't blame!

In this sentence, the understood subject is you:

• (ты) не вини себя = don't blame yourself

If you were speaking to more than one person, or to one person formally, you would say:

• Не вините себя за эту ошибку.

Because себя is the reflexive pronoun meaning oneself / yourself / himself / herself / themselves, and here it is the direct object of винить.

The verb pattern is:

• винить кого? = to blame whom?

So you need the reflexive pronoun in the appropriate object form:

• винить себя = to blame oneself / yourself

Not:

• себе — that is usually dative (to oneself / for oneself), which does not fit here
• ты — that is the subject form (you), not the object form

Because after за in this meaning, Russian uses the accusative case.

The pattern is:

• винить кого за что = to blame someone for something

So:

• кого? → себя
• за что? → за эту ошибку

That is why:

• эта ошибка (nominative: this mistake)
  becomes
• эту ошибку (accusative)

No. За has several meanings in Russian, depending on context and case.

Here it means for in the sense of because of or in connection with:

• винить кого-то за что-то = to blame someone for something

So in this sentence:

• за эту ошибку = for this mistake

This is a very common pattern, and it is worth learning as a chunk:

• винить себя за...
• винить кого-то за...

Both can relate to blame, but they are not always identical.

• винить = to blame
• обвинять = to accuse / to charge / to blame more formally or explicitly

In a personal, emotional sentence like this, винить себя is the most natural and common choice:

• Не вини себя = Don't blame yourself

Не обвиняй себя is also possible, but it can sound a bit stronger, heavier, or more formal depending on context.

So for everyday emotional reassurance, не вини себя is very natural.

Russian usually prefers the imperfective in negative commands of the type don't do X.

So:

• Не вини себя = Don't blame yourself

This sounds natural because it means don't engage in that action / don't keep doing that.

A perfective negative imperative is often used when the speaker means something like make sure you don't end up doing it even once, but with винить the normal, idiomatic choice here is the imperfective:

• Не вини себя...

So this is a good sentence to remember as a standard pattern, not as something unusual.

Yes.

Russian usually omits personal pronouns when the verb ending already makes the subject clear.

So:

• Не вини себя за эту ошибку.

really means:

• (Ты) не вини себя за эту ошибку.

Russian does not need to say ты unless there is some special emphasis, contrast, or emotional effect.

Yes. Russian word order is flexible, although the neutral order here is very natural:

• Не вини себя за эту ошибку.

You could also hear:

• За эту ошибку себя не вини.
• Себя за эту ошибку не вини.

These versions may shift emphasis:

• starting with за эту ошибку emphasizes for this mistake
• starting with себя emphasizes yourself

But for a learner, the original sentence is the best neutral model.

Not always. Себя is a reflexive pronoun, so its English translation depends on the subject:

• Я виню себя = I blame myself
• Ты винишь себя = You blame yourself
• Он винит себя = He blames himself
• Она винит себя = She blames herself
• Они винят себя = They blame themselves

So себя does not itself mean specifically yourself. It means oneself, and English changes it depending on who the subject is.

Use the plural/formal imperative:

• Не вините себя за эту ошибку.

So:

• Не вини себя... = to one person, informal
• Не вините себя... = to several people, or one person formally

This is a very important distinction in Russian.

The stress is:

• Не винИ себЯ за Эту ошИбку.

A learner-friendly pronunciation guide:

• ne vee-NEE see-BYA za EH-too a-SHEEB-koo

Main stressed syllables:

• вини́
• себя́
• э́ту
• оши́бку

Not naturally. In English, the normal translation is:

• Don't blame yourself for this mistake.

English usually says blame yourself for something, not accuse yourself for something.

If you use accuse, English more naturally says:

• accuse yourself of something

But for this Russian sentence, blame yourself is clearly the best translation.

A very useful pattern is:

• винить кого за что

Examples:

• Он винит меня за всё. = He blames me for everything.
• Не вини родителей за это. = Don't blame your parents for that.
• Она винит себя за случившееся. = She blames herself for what happened.

Your sentence fits this pattern exactly:

• Не вини себя за эту ошибку. = Don't blame yourself for this mistake.