Same problem here….

I do have a work around if you have an Apple TV use Music to play through it to use your Sonos.

Is there a fix for this error coming soon? Over a month now, anyone know what's going on with Sonos?

same here, I work for a software company and if we issued a version this bad we would lose all our clients.  

Same issue.   Has anyone spoke to client support for an update?  Last I did, there was supposed to be an update to resolve this issue at the end of the month but there is no indication an update is emerging.

Same issue.  Sonos support is pretty awful unless you are lucky enough to escalate to a higher-tier support tech who knows his/her stuff.  It’s a file sharing (SMB version) issue.  I am persuaded that the Sonos folks really don’t care.  They’ve already sold the products that no longer will stream the library that you purchased and ripped.  The executives have profited from the sales already, so why should they care?  The simple answer is:  they don’t.  

I just ran an update to the desktop Sonos App to 16.3 for the mac and it fixed nothing I still can not add my local music library. I still get the 913 error.

When will Sonos address this problem. Its been months now that I can no longer paly to my Arc what it is in my music library. 

same here and was on with support for over 2 hours and they where no help. 

I posted the steps below a couple of days ago in another thread.   I wrestled with the problem for hours over the course of a few days and finally hit on something that worked for me.  I can’t tell you how many different approaches I tried but it was a LOT!  Nothing from Sonos Support helped but I did learn something new with each call.  I’m no expert by any means, so if this doesn’t work for you, please don’t blame me or flame me.  And techies, please don’t make fun of me!   

I finally solved this (at least for me) after having 3 failed and lengthy support calls to Sonos.  I’m running Sonos 14.5 on a Mac Mini with Apple Silicon.  I’m no expert, but here is what I did:

1.  Settings -> General -> Sharing.  Disable (yes - disable) File Sharing and Media Sharing
2.  Settings -> Wifi -> click the “Details” button to get your IP address, write it down (e.g., 192.168.xxx.xxx)
3.  Settings -> Full Disk Access -> and uncheck anything to do with Sonos (for me it was “smbd”, “Sonos” and “Sonos Library Server”).
4. Using the IP address you wrote down, write down the path to your iTunes Media library with pen and paper.  I have my library stored on an Samsung external drive attached to the Mac Mini.  I used this path \\:192.xxx.xx.xxx\SamsungEXT\iTunes Media
5. Note:  your iTunes Folder Tree on the drive where your library is stored should have “iTunes Media” as the enclosing folder.  Your “Music” Folder should be a folder under the “iTunes Media” enclosing folder.  Under the iTunes Media enclosing folder will be other iTunes files/folders such as the *.itl and .xml files as well as “Automatically add . . . “, etc.
6. Reboot or shutdown the Mac and restart.  I did a cold boot (I shutdown completely and restarted). 
7. Settings -> General -> Sharing -> enable Sharing.  Enable Full Disk Access for all users.  Click the info icon and using the + or - buttons, add the following folders:  the name of the external drive where your Music library resides (this should be visible to you in Finder), along with the “Music” and the “iTunes Media” folders on that drive.  Make sure that all users and admins have Read and Write permissions for each folder and user.  Also, if “Sonos DMS” does not show up as a User, try adding it manually.  Under options for each users (including Sonos DMS), make sure “Share Files and Folders using SMB” is on.  
8. Make sure both File Sharing and Media Sharing are on (although I suspect that Media Sharing is not necessary, but what do I know?) 
9. Settings - Privacy & Security - Full Disk Access, make sure “smbd”, “Sonos” and “Sonos Library Server” have full disk access.  
10. Settings -> Privacy & Security -> Files and Folders -> Music, smbd, Sonos and Sonos Library Server should be listed.  If they are not, try adding them manually. 
11. Settings -> Privacy & Security -> Media & Apple Music.  Ensure Sonos is there with permission.  If not, add Sonos manually.
12. Open the Sonos app and click on Manage Music Library.   Add the path you wrote down using the NAS option, NOT the external drive option.  
13. Things should start percolating - if you have a large library, it will take a good while for indexing to complete. 
14. This took 4 days of trying everything under the sun and the above steps are what finally worked for me.  None of the first level Sonos techs were able to solve the problem.  I’m certainly no expert, but for me, the key was the disabling of Sharing permissions, rebooting and then re-enabling Sharing permissions that eventually led to everything working.  It’s been 5 days now and it all still works!  Of course, Sonos will probably release the updated App tomorrow that fixes this horrible bug - thanks so much, Sonos.  
15. For those of you who fear that you’ve lost your Music Library, I suspect that it has just been misplaced and well hidden by the new and “improved” (haha) app.  If you have any doubt, navigate to the folder where your music is located, and if it’s there, you haven’t lost it.  I guess now would be a good time to copy the library to a backup drive.  Good luck everyone and I’m sorry if this doesn’t work for you or if I’ve missed a step or further confused anyone.  I’m no techie, just an average Joe who is persistent and sometimes successful.  

I was finally able to add a folder from a Mac by using a longer path than the guide gave (instead of \\localname\Music, i put \\localname\externaldrivename\Music and that now shows as /Volumes/External Drive Name/Music). However that just seems to mean there is a path in the settings window- nothing shows in my library and when i run update library, it says it has run but it is still blank, so is not recognising or indexing any of the contents that used to be in my library...

And of course, after messing with this for days and finally getting things to work, Sonos released another app “update” a couple of days ago that has now rendered my external library invisible again.  Thanks for the incompetency Sonos - simply breathtaking!