An update: Browsing the forum lead me to understand that Sonos devices only support SMBv1. I was able find the SMB Protocol settings for my EX2Ultra and changed it to “SMB 1, SMB 2, SMB 3”. Sonos setup now seems to be able to reach the drive but now I’ve got some sort of permission issue. I have double-checked the Username and Password multiple times but:

The “Public” share definitely has public access turned on. Does anyone with a MyCloud know what setting I might be missing?

You might try the connection again, then submit a diagnostic to Sonos and post the number here. The Sonos folks can see your internal information from that and may be able to offer more information.

Thank you for the reply. How would I go about submitting a diagnostic?

https://support.sonos.com/s/article/141?language=en_US

Any further updates/resolution to this issue? 

I am experiencing the same issue at my end. 

Frequently, this error occurs when the NAS is not set up to accept SMB v1 connections, which is what the Sonos devices use to connect. There’s a thread here that discusses it. 

@Airgetlam - The setup is convoluted with WD MyCloudEX2Ultra. 

• WD admin control panel: SMB Protocol need to be set to 1,2,3
• Local computer: Since I have using a MAC - the file sharing option must be ticked off for Sonos App to see the drive
• Sonos App: Specify the audio files path on the NAS drive - it should update your library in 15-20 mins pending the size of your music library

Not an easy setup if you don’t know the sequence of actions to link to the audio files. For future readers fo this thread, I would suggest start with:

1. Start a chat assistance and get a case number detailing the issue
2. Call 1-800-680-2345 and hit option 3 for a faster transaction 
3. Provide your case number from chat assistance
4. They remote session on your computer - if you’re comfortable someone remote control your machine

It was resolved in 20 mins at my end. Sonos tech support was amazing!