older SONOS speakers no longer supported by SONOS applications and wont play?

If they haven’t been used in almost a year, the firmware is probably too out of date to add wirelessly.  Connect each device to your router with an Ethernet cable, then try to add.  Once they are added and updated, you can then deploy them wirelessly. 

It is also worth clearly distinguishing between:

Updating - bringing the software up to date for the operating system being used

and

Upgrading - moving from S1 to S2

If ​@jgatie’s suggestion to wire the speakers temporarily does not prove sufficient I would suggest you try the following

1. Continue to wire temporarily as advised by ​@jgatie 
2. Powee off all Sonos speakers
3. Uninstall all Sonos controllers apps on all devices
4. Power on your gen 1 Play:5 ONLY (while wired to router)
5. Download the Sonos S1 app on a mobile device and see if it offers you the option of “join existing system”.  If it does, then select that option.  You will need to enter your Sonos user name and password to access any settings.
6. See if you can now play music through the Play:5
7. If you don’t get the option to join existing system, choose to Set Up New System and follow the prompts  (If you go down this route you will lose all Sonos playlists and other customisations, so be prepared for that

Please post back at that point, whether it has gone well or badly!

In some cases, a well-out-of-date system needs Sonos’ help to get an interim update or two, which they should provide for you - they certainly have done for others… Contact Sonos support and see what they say. 

I ended up chatting to someone in support and it was resolved. His name escapes me but began with a J and deserves a mention, so my bad. It was a long process but it all worked in the end. I don’t like two different apps supporting different devices. It is not what I’m used to with Sonos. They should have thought this through and invested in software development which allowed older devices to connect and just not offer certain features that only newer devices can offer. Sonos has always been incredibly easy to set up and use (and sound great), but this dual app nonsense has taken them a step backwards.

It did indeed involve resetting the app, resetting the Play 5 and plugging it in to the network with an ethernet cable. It needed an update, as did the Playbase but after it was all done I changed the network back to wireless and it worked fine.

That's great news. The speakers that are now supported only within S1 have 32MB of RAM. That was a lot when they were designed and manufactured but impossible to include those without holding back the latest developments 

But you are revisiting a debate that was done to death at the time of the S1/S2 separation. I'm not going there again.

If Sonos wrote all of their software that might have been a possibility but they use software from the Linux project at the core of their devices and the Linux folks made some key changes that increased the memory requirements. Then the Samba (SMB networking) folks did the same and there just was no way to fit the new, bigger core software into the old low RAM/ROM devices.

That happens a lot with embedded devices, too small, less durable, too slow are common issues. Not from bad decisions when the systems were built but economic/technical necessities. Ones that are no longer as strict so modern devices seem fine, but that is for now, they too will not age well as requirements keep evolving and improving. Some backwards compatibility can be built in or reverse engineered but that is far too limited to make most users happy. You can research what was available and when to see the issues here. Sonos didn’t put in junk back then, but near leading edge bits, just too long in tooth today.

I have a rather large stack of ARM 32 bit driven hardware around here, some painfully expensive, and the OS folks have mentioned “we are done doing 32 bit releases” which leaves me with no options outside running old software (think Sonos S1) that isn’t going to make me happy. I also see the point it will have to be discarded as usable kit (think SMB v1) and I’ll have to bin the lot and move on.

Once upon a time we would all be considering the cost of ditching and replacing, and let’s face it, Sonos is not cheap. Now though, on top of all that, I picture a bulldozer raking it all in to a big hole. This is what companies need to avoid and design products to be repairable or modular and supported. I have managed to get mine all working again, which is great but could do without the constant nags about a new version which isn’t going to work. Users should be able to switch this off. We are also now at the mercy of businesses like Apple to keep supporting the older S1 in IOS.

Did you try this? 

I certainly would try that if I could find it. I’ve searched everywhere!

I have the same problem as ​@PhilfyPhil , as of the other day. Before that everything was working fine for a long time. Sonos1 won't recognise my system, and after re-installing the system and opening Sonos1 app I just get re-directed to Sonos2 app, which says my speakers are not compatible.

​@PhilfyPhil  how did you solve it?