Mieliśmy zrobić aktualizację systemu, ale w biurze nie było zasięgu.

Here Mieliśmy zrobić means something like We were supposed to do or We were meant to do.

Literally:

• mieliśmy = we had
• zrobić = to do / to make

But in Polish, mieć + infinitive often expresses an obligation, plan, or expectation:

• Miałem zadzwonić. = I was supposed to call.
• Mieliśmy wyjść wcześniej. = We were supposed to leave earlier.

So in this sentence, it does not simply mean we had done. It means there was a plan or expectation to do the update.

These two forms are similar, but they do not mean exactly the same thing.

• mieliśmy zrobić = we were supposed to do
• musieliśmy zrobić = we had to do / we were forced to do

So mieliśmy usually sounds a bit softer and can suggest:

• a plan
• an arrangement
• an expectation
• a task that was intended

Meanwhile musieliśmy suggests stronger necessity.

Compare:

• Mieliśmy zrobić aktualizację = We were supposed to do the update.
• Musieliśmy zrobić aktualizację = We had to do the update.

In your sentence, mieliśmy fits well because the second part explains why the plan did not happen: there was no signal.

It is in the infinitive because it follows mieliśmy in the pattern mieć + infinitive.

This is a very common structure in Polish:

• Mam pracować jutro. = I am supposed to work tomorrow.
• Miałeś to sprawdzić. = You were supposed to check that.
• Mieliśmy zrobić aktualizację. = We were supposed to do an update.

So zrobić stays in the basic dictionary form because it depends on mieliśmy.

This is about aspect, which is very important in Polish verbs.

• robić = imperfective
• zrobić = perfective

Here zrobić is used because the sentence refers to completing a single action: doing the update as a finished task.

So:

• robić aktualizację can suggest the process of doing it
• zrobić aktualizację suggests carrying it out and completing it

Since updates are usually thought of as a one-time completed task, zrobić is the natural choice here.

Because aktualizację is the accusative singular form, and it is the direct object of zrobić.

The basic form is:

• aktualizacja = update

But after a verb like zrobić, the direct object usually goes into the accusative:

• zrobić aktualizację = to do an update

This noun is feminine, and many feminine nouns ending in -a change like this:

• nominative: aktualizacja
• accusative: aktualizację

Other examples:

• mam kawę from kawa
• widzę kobietę from kobieta

Because systemu is the genitive singular form of system.

The phrase aktualizacja systemu means system update or more literally update of the system.

In Polish, when one noun modifies another like this, the second noun is often put in the genitive:

• aktualizacja systemu = update of the system
• koniec filmu = end of the film
• kolor samochodu = color of the car

So:

• system = nominative
• systemu = genitive

Because after w meaning in, Polish normally uses the locative case.

• biuro = office
• w biurze = in the office

This is a standard pattern:

• w domu = in the house
• w sklepie = in the shop
• w mieście = in the city
• w biurze = in the office

So biurze is the locative singular form of biuro.

It means there was no signal / no reception.

Breaking it down:

• nie było = there was not / there wasn't
• zasięgu = signal, range, reception (in the genitive form)

In context, zasięg usually refers to phone or network signal. So this sentence most naturally means there was no mobile signal or network reception in the office.

Depending on the situation, English translations could be:

• there was no signal
• there was no reception
• there was no network coverage

Because after nie było Polish normally uses the genitive.

This is a very common pattern in negative existential sentences:

• Był problem. = There was a problem.
• Nie było problemu. = There was no problem.

So:

• zasięg = nominative
• zasięgu = genitive

That is why Polish says:

• nie było zasięgu not
• nie było zasięg

This structure is extremely common and worth memorizing.

Yes. Zasięg is a broad word and depends on context.

It can refer to:

• mobile phone signal
• network coverage
• reception
• range

In everyday situations, nie było zasięgu often means:

• no phone signal
• poor mobile coverage

But in a sentence about a system update, many learners may also think about internet access. The Polish phrase itself does not specify exactly which kind of signal; the context has to tell you.

Yes, Polish word order is more flexible than English word order.

The sentence:

• Mieliśmy zrobić aktualizację systemu, ale w biurze nie było zasięgu.

is neutral and natural.

But you could also hear:

• Mieliśmy zrobić aktualizację systemu, ale nie było zasięgu w biurze.
• Ale w biurze nie było zasięgu, więc nie zrobiliśmy aktualizacji.

The original version puts w biurze before nie było zasięgu, which naturally sets the scene: in the office, there was no signal.

So the word order is mainly about emphasis and flow, not basic meaning.

Yes, it is very natural and standard.

• aktualizacja systemu = system update

In technical or IT contexts, Polish speakers also use related phrases such as:

• uaktualnienie systemu
• update systemu in more informal or borrowed tech language

But aktualizacja systemu is fully correct, clear, and natural Polish.

Yes, that is the natural implication.

The first part says:

• Mieliśmy zrobić aktualizację systemu = We were supposed to do the system update.

The second part gives the reason it did not happen as planned:

• ale w biurze nie było zasięgu = but there was no signal in the office.

So together, the sentence strongly suggests:

• the update was planned
• they could not do it then
• lack of signal prevented it

It does not explicitly say we didn't do it, but that is the very likely interpretation.