Regnskapsprogrammet fungerer godt, bortsett fra at fakturanummeret er feil.

Regnskapsprogrammet is made up of:

• regnskap = accounting
• program = program/software
• -met = the definite ending for a neuter noun

So regnskapsprogrammet means the accounting program/software.

This is a very common Norwegian pattern: nouns are often joined together into one compound word.

• regnskap
  • program → regnskapsprogram
• regnskapsprogrammet = the accounting program

Notice the -s- in the middle. That linking s often appears in compounds.

In Norwegian, definiteness is usually shown by attaching the definite article to the end of the noun.

So:

• et program = a program
• programmet = the program

The same happens here:

• et regnskapsprogram = an accounting program
• regnskapsprogrammet = the accounting program

This is one of the biggest differences from English. Instead of a separate word like the, Norwegian often adds the definiteness directly to the noun.

Because godt is an adverb here, not an adjective.

• god = good
• godt = well

In this sentence, godt describes how the software functions:

• Programmet fungerer godt = The program works well

Compare:

• et godt program = a good program
  Here godt is an adjective describing the noun program
• Programmet fungerer godt = The program works well
  Here godt is an adverb describing the verb fungerer

English often uses good where Norwegian uses godt.

Fungerer godt means works well / functions well.

• Regnskapsprogrammet fungerer godt = The accounting software works well

If you said er godt, that would usually mean is good, but that sounds less natural here because software is something that typically works/functions, rather than simply is good.

So for machines, tools, systems, and software, fungerer godt is very natural.

Bortsett fra at means except that.

So:

• Regnskapsprogrammet fungerer godt, bortsett fra at fakturanummeret er feil.
• The accounting software works well, except that the invoice number is wrong.

Useful related phrases:

• bortsett fra = except for / apart from
• bortsett fra at ... = except that ...

Examples:

• Alt er bra, bortsett fra været. = Everything is good, except for the weather.
• Alt er bra, bortsett fra at det regner. = Everything is good, except that it’s raining.

Use at when a whole clause follows.

Because what follows is a full clause:

• fakturanummeret er feil

That clause has its own subject and verb:

• fakturanummeret = subject
• er = verb

So Norwegian uses at to introduce it:

• bortsett fra at fakturanummeret er feil = except that the invoice number is wrong

If only a noun or noun phrase follows, you do not use at:

• bortsett fra fakturanummeret = except for the invoice number

Fakturanummeret means the invoice number.

It breaks down like this:

• faktura = invoice
• nummer = number
• -et = the definite ending

So:

• et fakturanummer = an invoice number
• fakturanummeret = the invoice number

It is definite because the sentence refers to a specific number in the software, not just any invoice number in general.

Because feil is the normal form here.

In Norwegian, feil can function as an adjective meaning wrong/incorrect:

• Nummeret er feil. = The number is wrong.

It can also be a noun:

• Det er en feil. = There is a mistake/error.

In your sentence, feil is being used adjectivally after er:

• fakturanummeret er feil = the invoice number is wrong

You do not say feilt here.

Because after at, Norwegian usually has normal subordinate-clause word order.

That means:

• subject + verb

So:

• at fakturanummeret er feil

not:

• at er fakturanummeret feil

This is different from main clauses, where Norwegian often has the verb in second position.

Compare:

• Fakturanummeret er feil. = The invoice number is wrong.
  Main clause
• ... bortsett fra at fakturanummeret er feil. = ... except that the invoice number is wrong.
  Subordinate clause

Usually, bortsett fra at is the more natural choice here.

Unntatt often works more like except in lists or formal contexts, and unntatt at is less natural in everyday sentences like this one.

So this sentence is best as:

• bortsett fra at fakturanummeret er feil

If you want a simple rule:

• use bortsett fra at for except that
• use bortsett fra + noun for except for + noun

Yes. In many contexts, program in Norwegian can refer to software.

So regnskapsprogrammet could be translated as:

• the accounting program
• the accounting software

The best English choice depends on context. If this is about a computer application, accounting software is often the most natural translation.

Yes, it is normal and helpful here.

The comma separates the main statement from the exception:

• Regnskapsprogrammet fungerer godt
• bortsett fra at fakturanummeret er feil

In modern Norwegian, comma use can be a little less rigid in some cases than in English, but in a sentence like this, the comma is very natural and clear.

Approximate pronunciation tips:

• regnskapsprogrammet
  roughly: RENG-skaps-pro-GRAM-met
  The gn in regn is tricky; in many dialects it sounds more like rengn or rein depending on the word and speaker, but learners do not need to worry too much at first.

• fungerer
  roughly: foong-EH-rer

• bortsett fra
  roughly: BORT-sett fra

• fakturanummeret
  roughly: fak-TOO-ra-num-mer-et

• feil
  roughly: file in English, but with a Norwegian vowel quality

Pronunciation varies by dialect, so the most important thing is to learn a standard pronunciation and be understood.

Yes. A few natural alternatives are:

• Regnskapsprogrammet fungerer bra, bortsett fra at fakturanummeret er feil.
• Regnskapsprogrammet fungerer fint, bortsett fra at fakturanummeret er feil.
• Regnskapsprogrammet fungerer godt, men fakturanummeret er feil.

These are similar, but not identical:

• godt = well
• bra = well/good
• fint = fine/well
• men = but

Your original sentence is completely natural and slightly more precise/formal than some of the alternatives.