Translation

I checked your file, there are two lines which contain errors. You have double quotes within the strings which is not allowed.

E.g. the string

contains double quotes near "Null", "Nej" ....
As double quotes are delimiters for the language string, they must be used only twice in one string - at the beginning and the end. Double quotes within a double quoted string must be coded as "_QQ_"
So the above string must be coded as follows:....if you want to use double quotes.

For readability reasons, you may also use single quotes, such as... as long as the string is not intended to be stored in a database. Storing it in a database would be messed up with single quotes as MySQL uses single quotes as string delimiter.

I will correct the file and put a new version in our download repository.
I checked it with the above strings changed and it worked.

Is it showing no Danish language at all or only a few language strings in English?
Does it affect all components or KISS Advertiser only?

The language settings are ok.
Have you defined your language as default language? Having a look at the 'installed' languages, there should be a yellow star in the 'default' column.