An update makes all your Sonos devices start up in a short period of time. Some routers get confused by this, which can lead to the problems you describe. You could try to take the power off all your Sonos devices and your router and start everything up again one by one, starting with the router.

If the sequenced power-up works consider adding static/reserved IP addresses to avoid this next time. Usually easily done from your router’s DHCP settings page.

sound bar and sonos sub,  drops off and wont joint with amp or playbar. When joined it drops off playbar is wired  Any suggestions

Im having same issues. Things are getting worse!  I am ready to boot the 17 pieces that have.  I purchased all new amps. everything is hard wired through a dumb switch and I reboot the entire house.

1. Grouping and ungrouping doesnt work or takes many retries.
2. Original sonos playbar (also wired) is paired with black sub. Streaming or local music on NAS stop , but stay on the sonos amp, but playbar and sub drop off. 
3. It was mentioned v16 would fix this, but now worse. Any suggestions. 

I would hold off on sonos purchases unless  we start seeing postings that say “problem resolved”

If you didn’t have all the Sonos powered off when you rebooted the router, you didn’t get all the benefit of the process. Although it might be simpler for you to reserve IP addresses for your Sonos devices in your router. Wired or WiFi, duplicate IP addresses can happen. 

So I've just had complete failures across my SONOS setup, for the past THREE hours been trying to get it all working and seems it's because SONOS have updated software

Nice one, yet another reason I'm thinking about chucking the whole setup. Honestly it's getting worse having SONOS now. 

Not really enough information to begin to point you in any possible direction. 

Random suggestion; wire one Sonos device to your router with a Ethernet cable, temporarily. 

Another random suggestion: look at your router’s manual, and set up reserved IP addresses for your Sonos devices (frankly, any ‘permanent’ device in your home). This might make a difference, with wired, SonosNet, or WiFi connections. 

I've literally turned everything off barring the playbar which is now connected via ethernet, keeps stopping when it attempts to update playbar with error code 800

Nothing re broadband has changed

I’m not familiar with an error code 800. However, Sonos has an FAQ for that error. 

Things they don’t mention, but I would still check for is VPN, port blocking, DNS issues, work profiles, or virus protection programs which might keep the Sonos speakers from reaching the Sonos update servers. 

Have you tried to call Sonos Support directly to discuss it?

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

I’ve been on chat for an hour two times now, both times failed to sort this. Tried my other speakers and they have managed to go on. But the Playbar both via wifi & ethernet will not register yet it’s on my account.

To say I’m frustrated that it just decided to do this yet it’s something to do with my internet / home is unbelievable.

So I’m stuck with my playbar at “not registered” and white light and I can’t help think it’s this wonderful update

It might be a fault in your PLAYBAR. Is it wired directly to your router with an Ethernet cable for now?

I’m not sure I understand what ‘it’s on my account’ really means. Do you mean it shows up on your account at www.sonos.com, or do you mean it shows up in your controller as ‘needs an update’ there? 

Are you running S1 or S2 for your Sonos? What router do you have? Are you running any VPNs, work profiles, virus protection, or port blocking software? What device are you trying to update your PLAYBAR with? What other Sonos devices do you have? What did Sonos Support suggest, when you provided them with a diagnostic? Have you tried powering off all other Sonos devices, and running the update with only the PLAYBAR connected? What exactly suggests it needs an update? Can you post a screen capture of this? Usually a white LED means it is just connected, per the LED states FAQ.