Are you connecting to your existing system and then using the ADD option?

Are all on the latest software release?

Add option from my existing system yeah,

I think they are all up to date since the Ikea one did it's update during the setup and I dont see any option to force an update.

Hi ​@Terry94 

Welcome to the Sonos Community!

Sorry to hear of this issue you are having with grouping your speakers to play together.

Generally, the error report you see is given when the speakers are not all running the same version of the software, as ​@Stanley_4 suggested.

To ensure your speakers are all up-to-date, please go to Settings Icon » Manage » System Updates » Check for Updates.

I hope this helps.

Edit: I just looked, and it is your Symfonisk speaker that needs the update.

Run the update but if the problem persists verify it was properly applied.

You can see that in the Settings - About menu, looks like: Version: 82.2-59204

 This issue occurred with the latest update of the app. I haven't been able to use my IKEA lamp speaker since. The app just doesn't recognize him. Reset, factory setting, router reset and update check... all without success. I had this problem about 1.5 years ago. At some point it went again after Sonos had fixed the bug in the app. Very very annoying and for me a reason to look for another system that I can start without an app. 

Hi ​@Kerkra 

Welcome to the Sonos Community!

Sorry to hear of this issue you are having. I can only recommend you get in touch with our technical support team who have tools at their disposal that will allow them to give you advice specific to your Sonos system and what it reports.

I hope they are able to help you.