Is it just voice response that’s silent? Does anything play if you use the app? Does the radio station get selected or does it stay on whatever was previously selected? 

Hi and thanks for your reply.

I can play music through the app so it's just the voice command.

It just stays on what was playing and if I say "Alexa, stop" the music just carries on.

I di get the chime and Alexa confirms the voice command. It just doesn't execute the command

Are you setting up for first time, or was it working but now not working? Have you tried specifying the room with the command? “Play x in kitchen”. 

Hi again

It used to work but then stopped. 

I just tried the command you suggested but no joy there.

If I ask Alexa about the time, the weather forecast etc. there's no problem.

If I say "play radio five live" I get the the reply back "playing radio five live from BBC sounds" but then nothing.

I've deleted and reinstalled both the app and Alexa but no joy

I have the same issue on my Era 100 when asking for any music (e.g. Spotify). If there is currently no audio playing, I can see the playlist/station load in the app, but it stays in the Paused state. If I ask a second time, playback starts. I’ve tried deregistering from Alexa, removed the Sonos skill, and adding back, but no change in behavior. Requesting the same content via Sonos Voice Control works correctly. 

I have the same problem on my Sonos one. The skill used to work, but it no longer does. Alexa will acknowledge receipt of my command by repeating it verbatim, but it does not execute the command. I the speaker remains silent.