Try removing SoundCloud from your music services in the Sonos app and re-adding it.

My Soundcloud stopped playing My Stream on Sonos as well, even after removing and re-installing the service on Sonos app

Did you try a reboot of your router, perchance? Or maybe 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 Sonos system and network.

Same problems at my Sonos…. Can’t add Soundcloud tracks from stream. :( 

Did you submit that diagnostic, as I suggested, and call in?

Same problem here with Soundcloud - “Unable to add songs to the queue”

Spotify, Amazon Music and TuneIn all work fine.

Did you submit that diagnostic, and call in?

Same problem here I have rebooted router, powered off all speakers, removed spud cloud account and re linked it. Still the same error. 
I have found an interim fix add to playlist and it plays via that route or select artist and play via that way. Not ideal for long term when you should be able to play direct from your stream. 
Any help much appreciated 

Did you submit a diagnostic while having the issue, and call Sonos directly?

No as they are closed Saturday and Sunday 

Any news about it?? I have the same problem since days

thx

Same problem. Unable to play stream from Soundcloud. Very frustrating 

This has been broken for weeks now. Sonos please.

Same Problem! frustrating

Sonos acknowledged it