Hi @cakebytheocean, 

Welcome to the Sonos Community. Thanks for reaching out to us with your concern and for sharing your feedback.  It would be great if you can provide us more details about the issue you encountered after updating to Big Sur for us to help you out. Also, if you can submit a diagnostic report for us to check for any errors. Just provide the confirmation number in your response to take a closer look. Please feel free to reach out if you have further questions or concerns, we’ll be glad to assist you. We'll wait for your response.

Thanks for checking in. Unfortunately I don’t get an error message. I try to add my itunes library, then it the sonos dashboard gets a spinning wheel on the top right, then nothing happens and my library is not connected. Above is a screen shot of the last step before it goes nowhere. 

Hi @cakebytheocean, 

Thank you for your response and for updating us. To further help you out with this, can you walk me through how you added your music library in the Sonos app and the device are you using? Did you receive any error messages when it failed?

I'd appreciate it if you could also send us a diagnostic report for us to check why you can't add your music library. Just include the confirmation number in your response. If you need help with any other information, please be sure to let us know.
 

I have the same problem as cake by the ocean.  I upgraded to Big Sur, I keep my iTunes library on a connected hard rive and when I try to update my library, nothing happens.  no error messages. just no playlists appear.  My Sonos speakers are now useless.  please help.

Did you send in the diagnostic report as was asked by the Sonos rep in the post immediately prior to yours? If so, posting the number here might help.