Now I can hear sound via hifiberry in kodi. I think it was the option „disable internal audio“ under „raspberry settings“. Now the error about hw:0 is also gone.
Shairport gets automatic stopped if you start kodi.
But now I have the problem, that (if kodi is stopped) my iPhone doesnt find the raspberry via airplay. If I choose „non“ as „installed hifiberry card“ my iPhone finds it.
And also squeezelite could not be started. Gives me the following errors:
[17:01:06.902331] test_open:384 playback open error: No such file or directory
[17:01:06.902516] output_init_common:382 unable to open output device
Many thanks for your help!