This is just a notice in case anyone else has the same issue while they have the Early Access Program feature of 'Dsign System' switched on.
If you try to add a RADIUS Server to a 802.1x SSID and then save your changes, you may receive the following message/alert about Open Roaming certificate not found:
After a bit of trouble shooting, while trying to make the same changes on different networks and different SSIDs I regularly got the same message/alert (But not always, at least I don't think it always did)
The solution was to switch to the old version view, by clicking on the link in the top right of the screen:
Once I switched back to the old version of the view, I could make all the radius server changes I wanted to without the messge/alert.
Anyway, just wanted to make people aware in case they came across this.