Hi @Johnny91, welcome to the Sonos community, and thank you for letting us know about your concern. Let me help you out on this.

First, I'd like to ask some questions to isolate the issue so we can determine the path towards a resolution.

1. What is the error message you received when you started to play music?
2. Any changes in the network recently?
3. Did you try removing and re-adding your music library?
4. Have you tried hardwiring one of your speakers to your router and update your music library?
5. Did you check the sharing permissions on your computer?
6. Did you check your Windows PC firewall configuration?
7. If you have an antivirus installed on your Windows PC, you may check the firewall configuration settings to ensure that it's not blocking Sonos.

Please run a diagnostic report from your Windows PC and reply back with the confirmation number for us to check and help provide a resolution. If you need help with any other information, please be sure to let us know. We'll wait for your reply.

Thanks for responding.

1. The music tracks apparently transfer to the Nokia 7.1 and are seen in its Music file. When I open Sonos S1 on phone, Browse to ‘on this mobile device’ then ‘Albums’ I see the album. I tap on Album and see the tracks. When I press play I get message starting with name of track, E.g. “Schindler’s List is no longer available on HMD Nokia 7.1”. It then cycles through all the tracks with the corresponding message at each track.
2.  I have moved a Play 1 to a different room.
3. Yes, I have tried deleting all music from mobile’s Music folder and at present moved back only 1 album.
4. Main speaker is always hard wired to router.
5. 6. 7. Will check asap

Hi @Johnny91, thank you for your response. If you’re still having the same issue after performing the steps we provided, it would be best for you to continue working with us over the phone to expedite the process. We really appreciate the time and effort you've spent in resolving this issue, I recommend contacting our Sonos Customer Care support to perform further troubleshooting and to do some tests on the Sonos app to isolate the issue to provide the best option for you. If you have any questions about this, If you need help with any other information, feel free to reach out. We and the community are always here to help.

I’m going to try a different android mobile

Hi @Johnny91, thank you for your response. If after trying different Android devices and you’re still getting the same results, please do reach out to our Sonos Customer Care. It would be best to continue working with your concern over the phone to perform real-time troubleshooting to determine the root cause and to give you options. If you have any questions about this. We and the community are always here to help.

I’ve now had success with the different Android, a Samsung J5 on Android 6.0.1. I removed the SD card from the Nokia and reformatted it in the Samsung.

I’ve now transferred a number of albums and can play them on my Sonos system.

I’ve an inkling that the problem is in my pc iTunes files as not all tracks transfer and play.

Hi @Johnny91, thank you for your response and for updating us. I’m glad that you can stream music on your Sonos app. On your music library, since we have provided you the basic troubleshooting steps and still having the same issue playing music, I’d still recommend contacting our phone support team to help you out. We're here to answer any further questions you have. You're always welcome here in the Community.