The folders issue isn't the main question - I just stumbled across this. In the meantime I got a third request to create a folder...
...no, the main issue here in this question is why Notation software stalls when I launch it the first time after boot when trying to open a file in it...
Only "dirty workaround" is starting Notation Software twice and open the file just with the second start. Dummy starting Notation Software seems to "initiate" anything here...
No I am not frustrated - it needs more for this...

... I'm just looking for a better solution than starting Notation Software always twice before opening a file...
I don't think all this here will influence my purchase decision much too. There are other things that are by far more important. The score transcription from midi files is really convincing - as well as transcriptions of what I play...