Have you called Sonos Support directly to discuss it?

It sounds to me like you may need to reset your library, following the instructions as explained in this thread,  but that’s just a guess. Calling in would confirm that, I’d think. And at the least, set you back on the correct path.

You haven’t noted what your native language is, and there is nothing on your forum account to indicate anything, but it’s likely that Sonos has a support phone in your language, if you click on the link I provided, you should be taken to the correct language’s contact page. 

So does this sound familiar…… 8 days ago my system worked as well as expected play my tunes through Spotify so all good everything working …. Then Mr Magoo at your factory decides to add a new update 8.1 00000000000000556565677788 whatever it is now and now here I am having connected my left and right Sonos SL’s then the SUB mini all I’ve got to do is add the beam and here we are, I connected the sub now NO left and right NOT IN THE SYSTEM I ADDED THEM TO 4 minutes ago. The sub needs speakers to work unison with sub (understandably) ALL I HAVE IN MY SYSTEM IS FKIN SUB MINI AND AN APP THATS FROZEN ON A PLAY LIST PLAYING RANDOM SONGS ON A SYSTEM ACCORDING TO YOUR APP THAT IS NOT THERE FFFFFSSSSSSFFFFSSSS HELLO EARTH CALLING SONOS FFS

Dude, chill.  If you added your “left and right Sonos SL’s” as a stereo pair, then you can’t add them as surrounds.  They need to be separated into two single speakers before you can add them to a soundbar.  

My native language is German.

I followed the provided link regarding that 913 error to no avail, not even by giving guest users access to the by now shared iTunes folder named “iTunes Media”.

What paths I used:

\\itunes-server\iTunes Media

and

\\itunes-server\iTunes-Media

just in case the “space” within the folder’s name iTunes used as standard name since ever iTunes existed would have to be somewhat “defined” by according ASCII equivalent. I even tried the paths I mentioned at the beginning of this post modified accordingly.

What I get as reply from the Sonos Mac app is something like:

“The volume within the provided path does not seem to be present anymore. Please check Your credentials.”

I do not understand why Sonos does not provide older versions of the desktop app at least for a while to keep long term customers happy until a working (!) update is published.

...and by the way:

Using an iOS device as source is no problem at all. But as far as I know the maximum capacity of an iOS device by now is about 1 GB of storage - not enough for my needs as source for home listening,

Can’t you add an external storage device or an internal SD card? No clue about Apple gear.

Well, all my media is located on external drives (USB HDs). The Mac mini’s internal SSD is far too small to host the whole library so this is no option.

When trying to add the music library hosted on an external drive directly connected to the Mac the operation of indexing does not even start throwing the 913 error (although following the guide mentioned on top).

When trying to add exactly the same drive as networked drive the indexing process stops in the middle of whatever mentioning the drive isn’t available anymore - although it is still mounted within the system.

I just stumbled over an interesting fact….

Once again I tried to add the library as being hosted on a networked drive (although it is connected directly to my mac). Choosing the NAS option with a modified path directly pointing to that drive without (!) the server’s network name before the rest of the path throws another ownership error like “wrong password / owner”.

I triple checked that

• the owner and rights are correct
• the password is correct
• the drive itself is defined as shared drive
• the folder holding the library is a shared folder

Everything as it should be and as it was before that update that ruined my former library access.

While the Sonos desktop app refuses to index whatever mourning about ownership name and password the drive and folder themselves are still accessible with exactly the same credentials the Sonos app refuses to use.

After getting in touch with Sonos support and sending the diagnostics to them they stated that SMB 1 is still running. As it is not possible to “delete” SMB 1 as network protocol I followed several instructions in here to deactivate SMB 1, again to no avail. I stumbled over an Apple post how to at least deactivate SMB 1 as fallback solution by using

sudo scutil --prefs com.apple.smb.server.plist get / d.add ProtocolVersionMap # 6 set / commit apply quit

Again: No changes, still no lokal music library can be indexed for the same reasons as before.

Right now I am following a new approach. As all my media (video and music) is spanned over several drives by “TuneSpan” I am connecting a completely new drive to where I am spanning solely the music right now (over 48.000 tracks...). After this I am trying to make Sonos use that drive. Will give a note if something changes.

Although I do not understand what actually has changed it seems I have found some sort of solution - and maybe the cause for all troubles.

After copying all my music files to a completely new drive and adding that to Sonos - nearly - everything works as expected.

First of all the direct connection to the Mac still does not work, that 913 error is existant. But now the networked use of that new drive seems to work. Adding that drive to the regular Mac OS file sharing went like expected, Sonos accepted the permission credentials - for what reason ever.

There are possibly two aspects that might (...) have caused all troubles, but as mentioned already I am not sure about this.

First of all the location of the music folder resides on a new drive, not at the regular path iTunes used to fetch up. In my special case my library is spanned by the Mac OS App “TuneSpan”. This app makes it possible to some sort of “relocate” very large iTunes libraries over several drives, not just the standard Mac OS startup volume. Before Sonos tried to get the library information from a folder called “iTunes Library” - note the space between the words of the folder’s name. I am just guessing that Sonos seems to have problems how to deal with non standard NETBIOS or SMB named folders - no matter what SMB version actually is used on a Mac running in Mojave. As said: Just a guess.

What I additionally noticed:

For some unknown reason there was another “Music”-folder within the regular iTunes Music folder the Sonos Mac OS App fetched up before that update. To explain this in deep a bit better: The german version of iTunes in Mac OS used to create a folder named “Musik” (note the “k”) to store music files. For some unknown reason I found another folder like that one. Within “Musik” (german) was another folder named “Music” (english). I do not know how this folder got there, not even when. Although this english folder exactly has the same permissions and network shares like the german one Sonos seems to stop any indexing process when it notices that english folder. Again: It’s just a guess.

Right now any music is stored within a new “Music” folder on a new drive, no other “Musik”- or whatever like folder in that one. Besides the 913 error everything seems to work now. But I have to re-add the whole iTunes library.

And then I can add new files that gathered within more than half a year of not being able to make use of Sonos...