Use Mac / Windows Desktop App. Solved this issue within minutes for me. Tried everything before like you with no luck.

Hi, i got same problem, All going well until it try’s to update and comes up with error code 1101.

Win desktop app, cannot config new device when you are new customer. 

need help guys :X

Same going on, new system set up, Beam is the first Sonos product I ever purchased. I got a Beam as a Fathers’ Day present. It connects to the TV just fine, but connecting the Sonos App to my Beam fails on the last step. At one point in the day, it recognized that I had a system, and the system consisted of a Beam. But now whenever I open the Sonos app, it prompts me to "Start update", and goes nowhere. I must have uninstalled and reinstalled the app 2 dozen times yesterday. Installed it on MULTIPLE devices.

I spent hours yesterday getting frustrated and no success. Is this happening with Sonos Arc as well? I'm ready to return this system!
 

Question: Where do I get the Windows app or a desktop app? 

To confirm to all, I managed to get it sorted , as long as you have a laptop /desktop which is not a chrome book you can hopefully download the app and then accept the update. Thanks to all for their advice 

Here's where you can download the desktop apps that can push firmware to your device:
https://support.sonos.com/en-us/downloads

Once the Sonos device is updated (it takes 5-10 mins), everything functions as expected.

Using the Desktop app instead of the mobile app worked for me also. 

Wish Sonos would mention this directly during the setup process!

Using the Desktop app instead of the mobile app worked for me also.