I have similar issues. Same error 1101. I can’t setup the arc using the Sonos app. That’s especially when I reach the part where I have to update. I’ve tried all the options that was given but to no avail. 
 

Have you tried using an ethernet cable to connect directly to your router?

Yes I did connected to router direct. Still same issue.

Not yet though. I’ll try that option and see. But coming from KOIDb, it seems that might not work. 

I have factory reset 6 times. Now it is dectected by Sonos App but still csnt update the Amp, it's now showing error 1106.

Having the same 1101 problem setting up my Ray - have tried Ethernet cable / resetting router etc. 

I was able to perform/finish the update using the Windows desktop app. After installing the Windows app, I was immediately prompted to update. This was immediately successful.

I was then able to add the speaker in the mobile app and assign it to a room.

Yes finally for me as well (the Arc). Some hoops but it turned good. this is what happened 

1. went through the mobile setup with my iPhone. Reached the point where I had to connect with WiFi and select which room, then got the 1101 error 
2. While the error was still existing on the phone. On my windows laptop I downloaded the Sonos software for windows and it said connect to existing system ( not set up a new one). 
    
3.  I went ahead in it detected the arc and prompted an update which I did. Afterwards I finished the setup. 
    
4. on the mobile I cleared the app from recent opened apps then restarted. 
    
5. I saw the option to join an existing system and voila. Done. Hope this helps. 

Hi @KOIDb et al

Welcome to the Sonos Community! Apologies for the delay.

We’d like to look into this error 1101 issue for you all. Could you please recreate the issue and submit a support diagnostic immediately after? Please post here to let me know you have done so, but please don’t share the number you are given at the end of the process. Thanks.

As @Emma2 mentions, you may find - if you have the option - that you are able to complete the updates from a different controller - please try updating from within the Desktop Controller for either macOS or Windows, if you can. You can download it here. Please be sure to submit diagnostics from your phone first, however.

I hope this helps.

Thank you @Emma2 !!! I was desperate after 10+ factory resets with brand new Arc. I could make software update with the sonos windows app… and now the ios app found the Arc.

so happy!

Hi! Got same problem with Sonos Ray.

Moderator Note - Removed and recorded diagnostics number.

Hi @KOIDb et al

We have identified an issue affecting some users where they receive a 1101 error when updating products. We are investigating, but do not have an ETA for a fix at this time.

In the meantime, you may be able to workaround this issue by performing the software updates via the Desktop app for Windows or Mac. If you already have the Desktop app installed, please reset the Desktop app after receiving the 1101 error in the mobile app before attempting the update from the Desktop controller (Help > Reset Controller). If you don’t already have the Desktop app installed, there's no need to reset it once it is installed. You can find the Desktop controller on our downloads page.

I hope this helps.

Since SONOS itself keeps suggesting customers using the Desktop Controllers as a workaround for all sorts of * the new crAPP does not do, may I suggest SONOS does not try to be courageous again an simply LEAVE THE DESKTOP CONTROLLERS alone for me to be able to at least listen to my Music until the day all S2 SONOS gear can fly out the door while I am waiting for new sound equipment to arrive.

*Moderator Note: Modified in accordance with the Community Code of Conduct.*