I am in exactly the same boat so I am anxious to hear if anyone has figured this out. 

After a 70 minute wait, ran through the usual steps w/ tech support and when that didn’t work was told it was the update and they were working on a fix. This was over 10 days ago…still waiting.

Sonos passing the buck and blaming my computer for not being able to access the local music library-(Of course, it just MIGHT have something to do with their update!) The advice I got from Sonos put the blame on my computer, but I got a different point of view elsewhere.

For what it's worth, I checked in with Apple support about the Sonos chat tech chap blaming my Mac for not being able to access my local music library due to"Legacy shares", and his recommendation that I make major changes on my Mac in order to fix the problem (How to disable SMB 1 or NetBIOS in macOS--link https://support.apple.com/en-us/102050 ) BTW this Apple support page  is for “enterprise and education system administrators”, NOT ordinary users). Does Sonos really put all the burden on their average user to figure out something like this? Some people just want to be able to use the product! And it used to work before their blasted update!

I didn't feel comfortable trying anything so complex without being certain that it wouldn't affect my Mac in a negative way,  and without any conviction it would actually fix my Sonos problem, which is something that Apple will not comment upon at all.

Let's just say that the Apple-specific recommendations the Sonos chap made for my Mac made no sense when I inquired about the ramifications for my Mac, and Apple support suggested I contact Sonos again as they "could not comment "on non-Apple products, and suggested I try to find someone at Sonos in tech support higher up with more expertise.

Sonos appears to be promising there will be an update in mid June regarding local music library playback, but I'll believe it when I see it. If they don't fix this, I will have to start looking for a different way to play my own music. I didn't get Sonos speakers just for streaming services. I want to listen to my own music, much of which is not available commercially.

What the heck is this advice I was given from the Sonos chat chap? This is so frustrating and galling.

This is so appalling. I've been playing music from my hard drive since getting my first Sonos not too long after they entered the market. I regret having committed to Sonos and no longer trust them.

SMB v1 is a sharing protocol (think of it as a language used to read files remotely) which allows your Sonos devices to access music stored on an NAS or computer.  SMB v1 has some well documented security issues, which resulted in a bunch of doom and gloom threads here and in the tech press about Sonos’ “vulnerabilities” due to the use of SMB v1.  Sonos appears to have caved to these scare tactics, despite the fact that there isn’t one documented case of a Sonos system being hijacked due to the vulnerabilities in SMB v1. 

The TL;DR version is you need to switch your sharing protocol from SMB v1 to SMB v2 or v3 and then your library will be accessible.  How to do that is something a Mac person could tell you.  My library is on an NAS and has been SMB v3 for a while.

I have this same problem.    Have been a loyal Sonos user for twenty years.   How do we get this fixed?

See if reverting to older version of the app works, it works on Android, local share works perfectly fine in is using the March version of the Software.

The problem has been latest software update by SONOS, so checking for solutions elsewhere will most likely result in total waste of time.

  They say they will have this personal library function back up by mid-June. Why would this take 6 weeks? It is entirely possible they are working through the programming and legal process of encrypting our music files to a Sonos only format network wide like iTunes did. The encryption program will likely be installed to run independent of the Sonos App and have a “corrective” program that will upload and reinstall the encryption if it is disabled. This way they can hold our music for ransom or even ruin/delete our music libraries. Sonos has demonstrated they are both capable and willing to take ownership of our systems and to force us to use kiddie-play marketing streaming services. 

  While my Sonos system in its current state in not useable, I have taken the opportunity to tidy up my audio files and move them to a Linux machine and a cold (i.e. unplugged) drive. I will use a laptop that has never run Sonos to download any more music. This way, Sonos can encrypt all they like and never have access to my master library files. I strongly urge everyone to do likewise.

 In the meantime, I am searching for a Linux based alternative like Kubi.

I am disgusted at Sonos. I have loved my system for many years and NEVER any issues. I have 7 zones in my house.  Ever since S2 came out I mysteriously have all kinds of connectivity issues. This is such a bait and switch. Where can we report this?

I am having the same problem.  I have used my music library with Sonos for more than 10 years.  It still works fine on my legacy S1 system.  But the new Sonos app simply can’t find my NAS drive.  As with others, I use Sonos to not just to stream, but to listen to my large library of music. 

Note that many of us have spent a lot of money buying multiple Sonos speakers to connect throughout our house.  So switching to another method of listening to music is not really a possibility.  They have a captive audience, and they can do what they want to us.