Synology NAS 'access to music folder denied'

​@MNB001, A quick Google search suggests that a bug in Synology DSM v7.1.1-xx could be the cause of this issue. The possible fix would be to either downgrade or upgrade, if feasible.

Try this (at your own risk..)

Not going to suggest that I’m smart enough to come up with the following. I posed your issues to ChatGPT and the below is what came back. FYI, I setup my Synology NAS library using its IP Address. I hope this helps.

Note that points 4 & 5 are bit off the normal solutions and require in-depth knowledge/skills. Again beyond my capabilities 😂
 

Yes. Based on everything you've described, I believe the problem is most likely related to SMB authentication or file permissions introduced when the Synology NAS was upgraded from DSM 6 to DSM 7.1.1.

The good news is that your Sonos S1 system can see the music library and display album artwork. That tells us the library indexing is working. However, indexing a music library and actually playing files from it are two different operations.

There are several things I would investigate before considering replacing the NAS or upgrading the Sonos equipment.

1. Check permissions on the actual music files

This would be my first recommendation.

You created a new user named Sonos and gave it read/write access to the Music shared folder. However, Synology DSM 7 can have additional permissions on individual folders and files.

It's possible that the new user can see the music directory but cannot read the actual audio files.

On your Synology:

Open DSM → File Station.

Right-click the Music shared folder.

Select Properties → Permission.

Verify that the Sonos user has read access.

Check whether those permissions apply to subfolders and files.

If necessary, apply the appropriate permissions recursively to the music library.

Be careful not to overwrite existing permissions for other users unnecessarily.

2. Check SMB settings beyond SMB1

Your older Sonos S1 hardware may require SMB1, depending on which Sonos products you own.

In Synology DSM:

Go to Control Panel → File Services → SMB.

Select Advanced Settings.

Confirm that the minimum SMB protocol is SMB1.

Leave the maximum protocol at SMB2 or SMB3.

Confirm that NTLMv1 authentication is enabled, if required by your older Sonos devices.

Also check whether SMB encryption is required. Older Sonos devices cannot use modern mandatory SMB encryption.

3. Try connecting by IP address instead of NAS name

This is a particularly useful troubleshooting test.

Currently, Sonos reports:

//DiskStation/Music

Try replacing the NAS hostname with its IP address, for example:

\\192.168.1.100\Music

Use the actual IP address assigned to your Synology.

Remove the existing Sonos library entry and add it again using the IP address, the Sonos username, and its password.

This eliminates possible NetBIOS or hostname-resolution problems.

4. A less obvious fix: Synology's Unix extensions setting

This is the most interesting possibility, particularly if the system contains older Sonos ZonePlayers or early Play speakers.

I found discussions in both the Sonos and Synology communities describing almost exactly this problem: SMB1 and NTLMv1 are enabled, but playback still fails with an access-denied message.

Some users resolved it by adding the following setting to Synology's Samba configuration:

This changes how Samba handles certain legacy SMB1 operations.

The reports include older Sonos systems running against DSM 7, where changing ordinary folder permissions did not resolve the issue.

However, this requires SSH access and modifying a system configuration file. I would not recommend attempting it until the simpler checks have been exhausted. Back up the configuration first, and be aware that DSM updates may overwrite manual changes.

5. Test with the dedicated Sonos account from the PC

This is an excellent way to distinguish a permissions problem from a Sonos compatibility problem.

On the PC, explicitly connect to the NAS using the new Sonos account, rather than the credentials normally used by the PC.

If that account cannot open and play the files, investigate Synology permissions.

If it can, the evidence points more strongly toward the legacy SMB connection used by Sonos, although the PC may be negotiating a newer SMB version.

My recommendation

Given that you've already enabled SMB1 and NTLMv1, I would prioritize:

Testing the actual music files with the dedicated Sonos account.

Trying the NAS IP address rather than DiskStation.

Investigating the unix extensions = no workaround if the first two tests fail.

One important security consideration: SMB1 and NTLMv1 are outdated and vulnerable protocols. Sonos confirms that S1 NAS sharing requires SMB1, so the safest long-term approach is to isolate legacy file sharing where possible.

I have one important question: Which Sonos speakers or components are in this S1 system?

Specifically, are they original ZonePlayers (ZP80, ZP90, ZP100, ZP120), first-generation Play:5 speakers, or newer S1-compatible products?

That distinction matters because the Synology Samba workaround appears particularly relevant to the oldest Sonos hardware.

I use Synology (all be it on s2) on latest DSM and must confess I have not read through all of this (so I hope I'm not duplicating) but you do need to give your Sonos user access to the SMB application…

Also network traffic and multiple concurrent NAS accesses/processing can also cause intermittent Sonos access timeouts...

​@MNB001, As mentioned yesterday, there appears to be a known bug in DSM 7.1.1-xx. This means you will not be successful using this specific DSM build.