I suspect there was an update to your Synology, in which they turned off SMB v1. There’s another thread about this issue already. 

Addendum;

Synology Music app connects to the NAS and the Sonos and works fine.

Sonos app can’t access the NAS anymore from Windows 10, MacBook or iOS.

I can play the NAS music via Mac, iOS and PC with other software.

SMBv1 is 100% enabled.

So, what did Sonos support say, when you submitted a system diagnostic within 10 minutes of experiencing this problem, and called Sonos Support to discuss it?

It seems unusual to me that this has affected only Synology users, and not anyone using other NAS devices, such as Buffalo, or Western Digital. 

I haven’t rang support yet. I’m not good with sitting on hold for ages.  Usually I can sort these things myself...

and I have NTLMv1 active

Did you deactivate “Unix extensions” in your SMB.conf?

Saw that mentioned somewhere on here.

Thanks Stanley but I can’t find any ‘Unix extensions’ reference in my Synology NAS settings.

Interestingly, when I use the Synology Music app to play through the Sonos the Sonos app can then control the music list I set up. The Sonos app is basically the only program and app I have that cannot use the NAS.

Sounds like a permissions issue. The other stuff working isn’t relevant, what is critical is the credentials (and mode) the Sonos speakers use to read files from your NAS. Th only folks that can tell you that are Sonos support, after you submit a diagnostic code and ask.

The Sonos app does not ever read the NAS (after Setup), its all done by the speakers.

Looks to be a standard SMB switch, should be there even if not documented. Trying it can’t hurt.

See:

controlav say ‘The Sonos app does not ever read the NAS (after Setup), its all done by the speakers.’

How can this be so if I have now three other apps that can play music from my NAS to the speaker?

Stanbley_4 sorry still can’t find smb.conf

The Sonos app / controller is only a remote control into what is running on the Sonos devices, it doesn’t do any playing/processing of the source material. This is also why SMB is being used to access the data on your NAS, as the Sonos devices are using a Linux kernel running on the CPU in the device, and there is no guaranty that the controller device, whichever one happens to be connected at the time, has access to the NAS. 

Rang Sonos help.  It’s a known problem with the Synology DSM 7.1.1 and unresolvable.

They suggest I ring Synology to help.  Pretty sure they will just say it’s ok with our Music app and Plex so take it up with Sonos.  Anyway, I’ll give it  a go...

I have the same problem where my Play 5 speakers no longer are able to play music from my Synology NAS.  The problem started without any updates to my NAS version.

I can access and play music with my Play 3 and Play 1 speakers, so it is only the Play 5’s that have the issue.

If i start music on a Play 1 or 3, then join a Play 5 to the group, it plays on all. If I then attempt to remove the 1 or 3, leaving just the 5, it stops playing again, giving the access denied error.

I’ve rebooted everything involved, and done a factory reset on the Play 5 to no avail…

UPDATE - Thanks to other users posting above, I followed the following fix to the Samba config file and this has fixed the issue for me. I can know play music across all my speakers.

Add the line unix extensions = no to the /etc/samba/smb.conf file 

This sounds promising.  Where can I find the Samba config file please?

I’m no Synology expert. I couldnt find how to add this setting via the GUI. I ended up connecting via FTP (using PUTTY) 

Log in with your usual admin account,

SUDO to root user - command is sudo su -

Browse to /etc/Samba/

The file is smb.conf

I used Linux VI tool to edit the file. ( Just google vi basic instructions to get the commands- again no exoert!)

i’d backup the conf file before you make changes, just incase it goes wrong.

If in doubt, I would raise the issue with Synology and get their advice on this fix.

Good luck. Hope it works for you too.

This is hard work!

How do I open the smb.conf file in VIM? I did Google help...

Try   cd \samba

I’m in the samba directory in vi telnet

drwxr-xr-x  3 root root 4096 May  5 07:15 .
drwxr-xr-x 50 root root 4096 May  5 09:07 ..
drwxr-xr-x  2 root root 4096 May  5 07:11 private
-rw-r--r--  1 root root  286 May  5 07:11 smb.conf
-rw-r--r--  1 root root 2425 Feb 24  2017 smb.conf.bak
-rw-------  1 root root  268 Dec 11  2017 smb.conf.eBfzeZ
-rw-r--r--  1 root root  270 Dec  8 09:26 smbinfo.conf
-rw-r--r--  1 root root 3773 May  5 07:15 smb.share.conf
chrisannesam@HopkinsNAS:/etc/samba$
 

but if i type ‘sudu vi smb.conf’ i get ‘-sh: sudu: command not found’

?

It’s sudo with an O and not sudu. LS shows the smb.conf so it should work fine for you.

Great.  All working again.  Thanks for sticking with me.