Unknown albumartist

Sometimes when i download a cd in flac and re- tag it,my audio system says unknown albumartist.

Can anyone help me with this strange issue.

I tried everything without success

Probably more to do with whatever you use to convert and burn the files back to CD Audio or are you burning them as FLAC?

Well, do you have an albumartist in these files?
If you do not have one, you can easily copy the ARTIST to the ALBUMARTIST field with an action of the type
format value for ALBUMARTIST and the
format string %artist%

Or could it be that you have stacked tags? What does the Tags column say?

No albumartist.
I copy the artist to the albumartist field and then i save it.

... and? I asked a couple more questions. If Mp3tag shows an albumartist then the car stereo doesn't find one?

It's not a car system it's my music system B&O beosound5.

Mp3tag shows indeed an albumartist....very strange isn't it?

Could you check what kind of tags are in your files? FLAC? V2.3? APE?
On shipment there is a column on the very right of the files list that shows the tags and their versions.
Andd we are talking about FLAC files, right?

Yes,we are talking about flac files.

Reference libflac 1.2

We had the case in the forum of flac files that had mp3-tags stacked on top of the flac tags. Ideally, falc files should contain only flac tags.
So it could be that the flac files come with mp3 tags, mp3tag writes flac tags and the player reads the unaltered mp3 tags.
so if you read the files and scroll the files list to the right then you should see the column "Tag" - and this should ideally show only FLAC.
That is why I am asking.

Yes now i see it.

Versie: flac(flac)

Versie: reference libflac 1.2...

That is the way it should be, I guess.
Is this a file that behaves in a strange way on the player?
If not, then try to find the differences to the strange files.
You may want to have a look at the Extended Tags dialogue for further investigation - press Alt-T for that.

Yes that's the file.

There i find

              Album
              Albumartist
              Artist
              Genre
              Title
              Year

As far as tagging is concerned, I do not have any ideas any more.
Common sources for strange behaviour may be a local database, unsupported character sets, unsupported tag versions, corrupted music files.
Or irregular spelling of fields - e.g. the player expects "album artist" but finds "albumartist" ...
But these things cannot be checked from the distance, sorry.