Der er blevet sendt en ny opdatering i nat, men jeg har ikke installeret den endnu.

Here der is a dummy subject, similar to English there in sentences like There has been an update sent.

In Danish, der er is very common when introducing the existence of something or when using certain passive-like structures:

• Der er en fejl. = There is an error.
• Der er blevet sendt en ny opdatering. = A new update has been sent.

So der does not mean a specific place here. It is just filling the subject slot.

This is a perfect passive construction.

It breaks down like this:

• er = present tense of at være
• blevet = past participle of at blive
• sendt = past participle of at sende

Together, er blevet sendt means has been sent.

A useful comparison:

• sender = sends / is sending
• blev sendt = was sent
• er sendt = is sent / has been sent, depending on context
• er blevet sendt = has been sent

So this is the Danish way to express that the sending happened before now and is relevant now.

Both can exist, but they are not always used in exactly the same way.

• er sendt can sometimes sound more like a resulting state: is sent / has been sent
• er blevet sendt more clearly emphasizes the event/process of being sent

In modern Danish, er blevet sendt is often the safest and clearest way to say has been sent in the passive.

So:

• Der er sendt en ny opdatering = possible, often a bit shorter and less explicit
• Der er blevet sendt en ny opdatering = clearly a new update has been sent

Because opdatering is a common gender noun in Danish, so it takes en.

Danish nouns have two genders:

• common gender: en
• neuter: et

So:

• en opdatering
• en ny opdatering

Also notice that the adjective matches the noun:

• with en words: ny
• with et words: nyt

For example:

• en ny opdatering
• et nyt program

I nat means tonight or last night, depending on context.

In this sentence, because the update has already been sent, i nat means last night / during the night.

Compare:

• i nat = tonight / last night
• om natten = at night / during the night in general

So:

• Der er blevet sendt en ny opdatering i nat = a specific night
• Serveren opdateres ofte om natten = something that happens at night generally

Yes. Danish often uses i nat for the night connected to the current day, and the exact meaning depends on context.

Examples:

• Earlier in the day: Vi ses i nat. = See you tonight.
• The next morning: Det regnede i nat. = It rained last night.

In your sentence, the perfect tense er blevet sendt makes it clear that the sending already happened, so i nat is understood as last night.

Because installeret here is the main verb in the perfect tense:

• har installeret = have installed

So the normal structure is:

• jeg har ikke installeret den endnu

Breaking it down:

• jeg = subject
• har = auxiliary verb
• ikke = negation
• installeret = past participle
• den = object
• endnu = yet

Jeg har den ikke installeret can exist in Danish, but it usually feels more like a resulting state: I don’t have it installed. That is a different nuance.

In Danish main clauses, the negation ikke usually comes after the finite verb.

Here the finite verb is har, so:

• jeg har ikke installeret den endnu

This is a very common Danish word order rule.

Compare:

• Jeg kommer ikke.
• Han er ikke hjemme.
• Vi har ikke set det.

So if there is an auxiliary like har, er, skal, vil, kan, ikke normally follows it.

Here endnu means yet.

It is especially common with negation:

• ikke ... endnu = not ... yet

So:

• jeg har ikke installeret den endnu = I have not installed it yet

Without negation, endnu can sometimes mean still, even, or another/further, depending on context, so it is a flexible word.

Examples:

• Er du der endnu? = Are you still there?
• Ikke endnu. = Not yet.
• endnu en fejl = yet another error

Den refers back to en ny opdatering.

Because opdatering is a common gender noun, the pronoun is den:

• en opdatering → den

If the noun were neuter, you would use det:

• et program → det

So:

• Jeg har ikke installeret den endnu = I have not installed it yet

Both parts connect past events to the present moment.

• Der er blevet sendt en ny opdatering i nat
  = the sending happened earlier, but it matters now
• jeg har ikke installeret den endnu
  = up to now, the installation has not happened

This is very similar to English present perfect usage.

Danish often uses the perfect tense with har or er when the past action is relevant to the present.

Because men is a coordinating conjunction, like English but.

After a coordinating conjunction, Danish normally keeps normal main-clause word order:

• ..., men jeg har ikke installeret den endnu.

Compare that with a subordinating conjunction such as fordi:

• ..., fordi jeg ikke har installeret den endnu.

Notice the difference:

• after men: jeg har ikke
• after fordi: jeg ikke har

So men does not trigger subordinate-clause word order.

Yes, but it changes the style slightly.

• jeg har ikke installeret den endnu sounds natural because den refers back to en ny opdatering
• jeg har ikke installeret opdateringen endnu is also correct and a bit more explicit

Danish often prefers a pronoun when the reference is already clear, just like English does with it.

Yes, sendt is natural, especially in technical contexts where an update is sent out, pushed, or delivered.

Depending on context, Danish could also use:

• udsendt = sent out / issued
• lagt ud = posted / made available
• rullet ud = rolled out

But sendt is simple, neutral, and very believable in a sentence about software or system updates.