Did you follow all the steps listed in this thread?

It doesn’t specifically cover error code 1, though.

One addition I’d make to that article is to connect the errant speaker to the router with an Ethernet cable temporarily, to help avoid some network issues. Not possible with some speakers, that’s probably why they omitted it. 

But if all of those steps don’t work, I’d certainly echo that posts suggestion to contact Sonos Support directly. 

Thanks for your reply.

I’ve not tried “Reboot your Sonos products” yet, so I’ll try it next holiday.

Although, I connected that Symfonisk speaker to another broadband router and internet line to which the existing Sonos system is not connected, and set it up as a new system, and I still got the same error, so I guess it won't go away even if I reboot all the speakers.
Anyway, I will try it first and contact Sonos support. Thank you.

This is self-reply. I’ve solved this problem with Sonos staff support.

The root cause was that Sonos S2 application cannot find and apply the appropriate firmware to the speaker(Symfonisk bookshelf gen1), and I solved this with Sonos S1 application. The technical support staff tell me the way to avoid error code 1 and the method to update the firmware twice with S1 and S2 apps.

Here are the steps.

1. Stop all S2 application on your smart phones
2. Install S1 application and start it.
3. Reset the speaker (factory reset) and restart. (waiting for set up)
4. Try update with S1 application and set up the speaker. → success!
5. Stop S1 application
6. Reset the speaker (factory reset) and restart. (waiting for set up)
7. Start S2 application.
8. Try update with S2 application and set up the speaker. → success!

My Gen 1 Book shelf updated fine, thankfully.
 

Whilst it’s great there is a work around if your speaker won’t update, what a palava! These speakers came out just before the S2 app was released and should have been optimized for S2. Imagine if you have to do that for each update?

I am glad I just tested 1 bookshelf and 1 table lamp when they were released and didn’t jump into buying loads. I have 3 pairs of S2 bookshelf’s now and am very happy.

In general, there really should be no “palaval” involved, at least if your network is working properly. I suspect there’s something odd, or there was at the time you were attempting to update the speaker, and it finally went through.

I’ve never had a “palaval” in updating any of my 20 plus speakers on my network. Either before the S1/S2 split, or after. 

It’s palava not palaval, and I was responding to the OP and their problem and the solution found.

Great, apologies for misreading the text on my screen. However, in general, there should not be any palava involved, as I suggested in my previous post. Any such would be an indication of something wrong in your system. Easily a problem on the Sonos side, but chance of that are relatively small, it’s much more likely to be a network issue outside of Sonos’ control. 

Contacting Sonos support is a good way for anyone to start to unwind the issue, as did the OP.