Delete the alarm completely. Then remove power from the speaker the alarm was on for two minutes, then plug it back in. Try setting up the alarm again.

if it continues to crash the controller, I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it.

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

Hi Bruce-

Argh. I don’t have time for this!   Now that that’s off my chest…

I really appreciate your speedy reply, and the steps you outline in your response make sense.

The alarm is on a Roam, so I’m not sure about the “remove power” -- I know how to shut it down by holding the button, but how “off” is it really?

Will try to find time to go through this process.

Thanks!

Ah, yea, that does make it a little harder. You do really need to make sure it is really turned off. You’re forcing (or trying, at least) a reboot of the operating system. Somewhere in the FAQs is how to really power down the Roam, if memory serves, you hold down that power button longer than you expect. Here it is. 
 

My conjecture is there’s something borked (technical term) in the OS running on that Roam, and deleting the alarm, forcing a reboot, and then re-setting the alarm might fix it. 
 

My fallback position remains providing hard data to Sonos, and calling them ;)

Hi Bruce-

Thanks! Yes, that’s how I think I turn the Roam “off” -- have done it before when the network connections got confused. Will try your process tomorrow (or the next day...) and will post results here I think I know something.

Appreciate the help!

Hi Bruce-

You solved it!

Shut down/wait/restart Roam had no effect (but I’d feel like an id10t to have not tried that first…)

Used desktop app to delete the alarms, powered down all the speakers (because what the rest were playing had been triggered by this morning’s alarm -- so make sure everyone forgets the alarms...), shut down all Sonos apps, waited minutes.

Powered all the speakers on, set up new alarms in desktop app (because it’s so much less hard to select MyTuner stations that way), then went to iOS app and I can access alarm settings, etc. without freezing the app. Will have to see that they actually go off in the morning as planned, but I don’t expect problems.

I’m new to Sonos — first speaker last December — so I’m still getting the hang of the system, and still unclear on where the ‘brains’ are.

As an old guy who was into audio when personal computers said “Altair” on the front, the idea of a self-contained, bi-amplified wireless speaker that tunes itself to the room is PFM/Jetsons — and wrapping my head around the idea that a “speaker” the size of a tall soda can has an operating system‽… I’ll get there eventually.

Thank you for the help!

I try never to feel badly when I’m contemplating technology that I don’t (yet) have an understanding of…but I’m glad your situation is resolved.

For all practical purposes, each Sonos device (except the BRIDGE/BOOST ones) is a small computer that drives the speaker. Which means each one run the OS (I think it is Linux) and stores all the data on it, including the alarms. That way, any number of controllers (I have 4 or 5?) can connect and show the same information, as they are just polling the info stored on the speakers. 

It’s not uncommon for many people to fall into the idea that data is stored at the controller level, but I think the current system is better. I happen to be connected at this moment to a friend’s Sonos system, and can see all his settings, but can’t change them, as I don’t have his house hold account password.  I can play music all day long (and have, using AirPlay 2), but can’t add or delete any streaming accounts. works extremely well. 

I do suspect there was something odd going on in the OS on the Roam, although it’s hard to think of a power surge causing an issue on a battery powered device. In any case, I think the forced reload of the OS on it ‘fixed’ whatever memory corruption there might have been that was causing the crash. 

Sometimes,  control alt delete really is the answer ;)