Detlev, it seems, you offered me a non-working solution. 
The case of blank fields after guess values is not resolved: Empty tag-field in "FLAC / Vorbis Comment" tag?
I ran into it, too.
Detlev, it seems, you offered me a non-working solution. The case of blank fields after guess values is not resolved: Empty tag-field in "FLAC / Vorbis Comment" tag?
I ran into it, too.