I’d first try a full ‘network refresh’. Try unplugging or powering down all your Sonos devices and your computer, then reboot your router. Wait two minutes, then power up all the Sonos devices and your computer. Wait another two minutes for everything to boot up and reconnect, then test. 

If this works, and I think it should, you may want to look into assigning reserved IP addresses in your router for most connected devices. This isn’t a requirement, but helps avoid this situation from occurring in the future. If this is too complicated, the above procedure works as well, and may be needed extremely rarely. 

However, if this doesn’t change things, I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it. Don’t post the resulting diagnostic number here, they get sensitive about GDPR.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

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

I had this happen to me on an iMac recently. It took a couple of times uninstalling and installing the desktop app again for the system to show. Didn’t have to do anything in relation to the speakers or router, as the system was loading correctly on all iPhones/iPads.

It happened to me also, try to uninstall the app and install it again :)

Thanks everyone - I’ll try reinstalling again first….

One thing that occurred to me was that maybe the speakers are linked to our WiFi extender as are our iphones, but the PC is on an Ethernet connection to the main router… When I’m feeling strong and calm () I’ll give re-booting everything a try.

Have you taken a look at the system requirements from the Sonos support site:

https://support.sonos.com/en-us/article/sonos-system-requirements
 

If you look in the “Unsupported Network Setups and Devices” you will see that extenders are not recommended. While it may have worked previously, the extender is probably the issue.

Sonos recommends using a mesh system to extend the WIFI coverage in your home if you are not able to hardwire an access point to do so.

OK….thanks…. but I’m a simple soul and wouldn’t want to start trying something like this in case other systems fell foul of it… I see on the support site that there are other problems with the mesh setup. At the moment, we’re happy managing out speakers from iphones. One day I’ll feel strong enough to reconfigure so that they all operate from the main router.