Hi @Jorschik, 

Welcome to the Sonos community. Thank you for reaching out to us and for letting us know about your concern.

To help you out with this, allow me to ask a few questions.

1. What is the error message you received when you tried to play music?
2. Have you tried removing and re-adding your music library?
3. Have you tried hardwiring one of your speakers to your router and update your music library?
4. Did you check the sharing permissions on your computer?

Please run a diagnostic from your Sonos system and reply back with the confirmation number for us to check and to help with a resolution.

If you need help with any other information, please be sure to let us know. We'll wait for your reply.

Check if SMB(v1) has been disabled on the My Cloud Home; this could e.g. happen during a firmware update, but Sonos needs SMB(v1) on the NAS https://support.sonos.com/s/article/78?language=en_US
 

Thanks a lot for your quick replies.

@Rowena B. 

1. The error message is „Keine Auswahl verfügbar“ („No choice available“)
2. Yes, I did
3. No. Sonos is otherwise connected (Radio etc).
4. I didn’t find any permissions needed for MyCloud home

Diagnostic confirmation number 183464771

thank you!

@ClausN Thank you! Not sure, how to check this. I am using a Mac… MyCloud Home does not show me such settings...

Western Digital just updated my MyCloud device with what they are calling OS5, which required me to go back in and reset (as memory serves) both the SamB v1 option, and the One other option. 
 

Some of this is covered in this thread :

There was another thread around about someone else who had to reset another setting, but I don’t recall where that thread was. 

Maybe this thread, the (for now) last post by jeepsterstuff regarding NTLM ?

Thanks, @ClausN, that’s the one I was indeed trying to remember. 

Dear all, many thanks for all your advice - much appreciated! with the help of the Sonos telephone support in Germany, we solved the issue  now. It appeared, that we needed to fix settings both in the new router and in Sonos and we had to re-set-up MyCloud Home in the Sonos app.

Ah, Germany. You probably should be aware of the forum auf Deutsch if you run in to further issues, and prefer the native language to English. ;)

Glad they were able to help. 

Great, thanks, Bruce, I wasn’t 

aware of a Deutsches Forum)))

Your English is perfect, just wanted to make sure you were aware of both ;)