Have you double checked with YouTube? As far as I know, all Sonos is doing is passing data to the authorization server maintained by YouTube, and displaying what response they’re getting. 

Last night, I deleted my Sonos app and reinstalled it, then reinstalled YTM and it allowed me to login. Now the YTM icon shows up and I can click it. When I do, it’s a blank gray screen that says No selections are available. There is nothing at all to click. When searching the forums, this seems to be a recurring issue.

I’d suggest that you call Sonos Support directly to discuss it.

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your Sonos system and network.

Yeah, I've done that twice before to no avail. Funny enough, I just checked the YTM forums about this question and they only refer the poster back to a Sonos forum on the subject. 

At least for the original problem, a total deletion and reinstall, as painful as it is, worked for me.

Hmm. Just made a last ditch call to support. First guy was completely unhelpful making me plug, unplug and reboot every device in my house for an hour. Told him it wouldn’t work. It didn't. So I asked to chat with someone else. Much more helpful. He did a little research and it appears that YouTube Music behaves differently from most other services here. With YTM Free, you can ONLY listen to music you’ve uploaded from your own library. WHAT?!! Who uploads music to their streaming service? All other features are crippled unless you are a YTM subscriber. Spotify doesn’t do that. 

Main issue is Sonos needs to be better at outlining this. Many other posters who have had the same issue for years don’t know this. Instead of “No selections are available” it should say, “You need to be a subscriber to experience all YTM features.” Honestly, Sonos could ask if the user is a subscriber much earlier, before they download it. Shady practice by Google and really sours me on YTM tbh, especially since the YTM app and browser access give me unencumbered streaming, playlists and recommendations. Seems like Sonos members are being unjustly shut out from YTM. Or is it Sonos seeing YTM as a Sonos Radio threat? At this point, don’t know, don’t care, not paying for either one. My time is worth more than figuring out all these vendor reindeer games. No one has a definitive answer.

Having said that, it still appears that several paid YTM users have the same issue. So who knows.

I have the same Problem. I can’t listen to YouTube music on my Sonos. It says it authorizes sucessfully just to tell me Error can’t authorise. It’s totally annoying. Any solution???

I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system

hey thanks for the reply!

i found a solution by myself and hope this will help anybody in future!

i tried multiple times on various phones that worked before, still got the Reauthorization Error

Then i switched to my Desktop PC downloaded the Sonos App for Windows and did it there. it worked right away.  Happy listening :)