Due to a hardware change* of our Wireless Network adapter you can not Enable the WiFi option in your settings in older firmware. The Riva screen needs at least firmware version 1008 in order to recognise the new module.
The new WiFi module model can be identified by the tag on the module 01WIMRA instead of 00WIMRA see picture below (shows the old model).
Update online to the latest version via System settings> Device> Online update in case you are on firmware v1007 or even older.
* Both models have the exact same functionality