Try removing YouTube Music from your music services in the Sonos app and re-adding it. You can also try resetting the Sonos app under App preferences and closing and restarting the app.

Hi, 

I just did , I receive the same :(

Have your tried rebooting your router?

Like restarting the network ?

Yes. 

Already did it , still the same unfortunately .. 

Hi @Christiane1991 

Welcome to the Sonos Community!

Are you still having this problem? If so, I recommend you get in touch with our technical support team who will be able to interrogate your Sonos devices as to what is going wrong and give you specific advice to help you.

When you have trouble with a music service, it’s always worth looking out our Service Status page for alerts (I realise this reply is a bit late for you to do that for this issue, but it helps to know if an issue is yours or theirs!).

Same issue just started today.  Only one of my YouTube playlist gets the error... The rest work.  Re authenticated twice.  Removed and added account.  Nothing helping... Not sure if I contact Sonos or Google

As suggested n the post before yours, it looks like Sonos, at least initially.

Spoke to Sonos Support... Was told issue had been reported to YouTube.   Hopefully, gets addressed.  Still can't see some of my playlists

Same, though my issue is with a playlist. Can't get in touch with technical support team, e-mails are ignored, chat is unavailable, and there's no phone number nor contact form for my country. Service Status page says "All Systems Operational".

It's suddenly working again.