I have all my music on my server.  I have a mix of Sonos products between S1 and S2. S1 can see the server, all the music but when i go to play says access to the sever is denied. S2 has no issue accessing or playing the same files on the server. Anyone have any ideas? Yes..i’ve removed and added my music several times, no issue with firewall, Server permissions are set correctly

So, if S1 can see the NAS, that means it is running SMB v1. Since S2 is getting a ‘denied’ access, have you tried submitting a system diagnostic within 10 minutes of experiencing this problem, and calling 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.

I'd say it was the other way around?

Access from S2 is fine so it's more likely a SMB1 issue with S1 unable to access the system and S2 fine (assuming same credentials used for both systems).

Check how to enable SMB1 on your NAS.

Apologies, I did read that backwards. But still, submitting the diagnostic from the non-functioning controller, and calling Sonos would be my recommendation. At the worst, you’d be providing hard data to Sonos about a bug, at the best, they’d be able to see something we’re not thinking of, and give you an immediate solution.

Thanks for that catch, @sjw . And I agree, it’s likely that enabling SMB v1 on the NAS would likely be the correct course of action. 

Just thought I’d update this as I’ve discovered another, less wearisome, workaround.

If I add new music to Sonos I obviously need to update the music library to hear it. When I initially did this I was removing and the adding all folders back in. No what happens is I add music, check the folders, if music is missing from a particular folder I remove just that folder and add that one back in. Nowhere near as laborious.

Also though, I added an album the other day and didn’t have to remove or add any folders. Wierd, but good.