@Darksejd,

As far as I’m aware, there’s no downgrade path with Sonos products. The only downgrade option I’ve seen, is to move a compatible device from S2 to an S1 system as outlined in this link:

https://support.sonos.com/en-us/article/downgrade-a-sonos-product-from-s2-to-s1

The CR200 controller is no longer supported by Sonos, so you’re most probably out of luck.

I did that, and can control the PLAY:5 just fine via the mobile S1-app. The problem is, I would like to use the CR200+PLAY:5 system without a phone/tablet, so guests can use it without getting my WiFi password.

The CR200 doesn’t work with the current Sonos App, or device firmware …and there is unfortunately no way back to the older version as far as I’m aware. It appears you’re out of luck as far as the old hardware controller is concerned… it maybe easier to buy a cheap new or used (compatible) android/fireOS mobile/table and let them loose with that instead.

Apparently there are ways to confine mobile devices to just the one (Sonos) App only, so you could perhaps explore that option a little more too. See this link:

https://www.techbout.com/lock-android-tablet-phone-to-one-app-16908/

Update (problem solved):

I chatted with Sonos support, and it turns out that the CR200 will work with a PLAY:5 if:

1. The PLAY:5 is downgraded to work with Sonos S1 (you can do this from the app yourself)
2. The PLAY:5 (or another unit in the same system) is connected directly to the network with a cable. In my setup, it works with a switch.
3. The CR200 must have a certain firmware version to work with the PLAY:5. I don't know which is new enough, mine's v7.5 (36477130), and it works.

-so if any of you is in the same situation; try the above or Sonos support chat before you throw out your CR200 :-)