Be sure your computer isn’t using the SMBv1 or HTTP file sharing protocol as Sonos no longer supports this.

You’re speaking Japanese to me. Can you walk me through this, and possible solutions? 

Sonos really slammed me face first into a pile of mud here, haven’t they?

First check the Home Screen on the new app. Do you see “Music Library” listed under “Your Sources”? If you don’t see it, try restarting the app a couple of times and see if it pops up after each restart:
 

I do not have my music library available after doing what you said. By the way, thank you for replying instead of up/down voting and moving along.

No problem.

What model computer is your music library stored on?

11th Gen Intel(R) Core(TM) i7-11390H @ 3.40GHz   2.92 GHz
DESKTOP-LLL1U7O
Dell Inspiron 15 5510
Windows 11 Home
 

Do you have the Sonos app on your computer? If not, download and install the Windows app from here:

https://support.sonos.com/en-us/downloads
 

Then follow the instructions on the link below to add your library. If your library has already been added, try removing it and re-adding it:

https://support.sonos.com/en-us/article/add-your-music-library-to-sonos#

Error adding music
Reason: Unable to add the shared folder to your music library (913)

Try the fix mentioned on this thread about folder permissions:

Sonos permissions were already granted and displayed. Still, I re applied permissions, restarted, and I’m still getting the same error.

There are similar horror stories all over that thread. This is not going to end well for me, is it? How can this happen with a premium brand like Sonos?

Does Airgetlam care to chime in here with another solution??

No, thank you, @GuitarSuperstar is more than capable of figuring out which issue you’re experiencing. I am following, and agreeing with his thoughts. 

Try disabling this setting (if available):

Tried that one as well, but didn’t work (same error).

I called support (and yes, waited on hold for over an hour). There were a lot of steps to get my library re-added.  I had to grant the staffer remote access to my computer, as well as numerous administrative permissions and Microsoft access.  One of the steps was indeed disabling SMB 1.0, but there were numerous additional steps.  I couldn’t reproduce the solution on my own if I tried.  I don’t know if Sonos will fix this issue, so best to bite the bullet and call.

Me too - only just found out after the update today

I got the 913 error and spent a load of time searching around for fixes - I only use Sonos for my local library, so useless to me without access. I’m not technical, but this worked, using a Windows10 PC:

1 Sort out SMBv1 - a simple search to find out how to disable SMBv1 and thus enable v2/3 is pretty straightforward and you can’t do any damage (ha!) though for a complete non-tech some of the steps may look a little threatening. And anyway you were warned about this.

2 Look for any of the guides at the top end of the 913 community rant - they’ll show how to make sure you are on a private network and nonpassword sharing is enabled; then it’s just a matter of right-clicking your music library folder and sharing with the Sonos wiFi system in the dropdown.

3 The really really really tricky bit. Do a TEOTTEO (turn it all off and on again), fire up Sonos on the PC and try to add your music library. Zero success. Doom, gloom. Try everything again from the start. Do this three or four times between emails to ceo@sonos.com with increasingly vulgar language. Wait a day. Start the music library addition and then quickly walk away from the machine for an hour or two. Don’t look back. When you return it will all be working. I can guarantee this method.

Of course this will not get you any of the search facilities you are used to. If you add a CD, say, you will release it into the Sonos aether with no trace, until you look for an individual song name. So ‘play album’ from a new CD with eight tracks will take about thirty minutes to accomplish, track by track without an index to help. This is progress in the Sonos universe. What are these bozos thinking? And the IoS app is another matter altogether, flailing around between libraries and rooms like a drunken sailor the night before an examination. Utterly useless for any purpose.

OK - i found the fix.  Ken’s answer below is the start.  But there is a second step.  This is for Windows PC (I don’t know about Apple products).  Follow Ken’s steps then after you add the Sonos to share, go back to the properties sharing tab.  Don’t do his step 3 yet.  Then click on the “Advanced Sharing” button in the middle of the dialog box.  Then in the upper left corner, check the box for advanced sharing.  Click Apply and close.  Then go to the Sonos app on your PC and add the My Music library.    It worked for me. 

I am VERY disappointed in Sonos’ tech help.  I even sent an email to the CEO (since they don’t give any other email addresses for help).  No one responded to calls, chats or email.  But I am glad we ca figure this out.

Good luck…let me know if this works for you.

Curses, Sonos.  Three weeks and counting...they really messed up everything from Music Library to Music Services on all the Sonos apps (PC desktop, Ipad, Google smartphone).

Same thing here.

SMB1.0 turned off.

File sharing and security permission all granted to Sonos Wireless HiFi System. And upon the suggestion of Sonos Help Desk, created second user under Windows 11 Accounts/Users. Gave same file sharing and security permission.

Nothing works. Help Desk claims issue escalated and an invitation to fix it will come. Have not seen it.

How can Sonos be so bad?

My Sonos Music Library has been “updating” for almost 24 hours. I’m so sorry that I bought this crummy product. It will work fine, until it doesn’t, and then you’re faced with HOURS of dealing with it.