Hi Norstorm,
As mentioned in the link that Carlos previously provided, two networks (and IPs) on the same computer can’t be used simultaneously. Please disconnect the ethernet cable from the computer and then connect Cubase iC Pro using the Wi-Fi (Wireless LAN) option of your system.
Are you btw trying to connect to your local Wifi network or directly to an ad-hoc connection between your PC and your iPad? Ad-hoc connection between Apple devices and PC computers sometimes turns out to be unreliable, we’d highly suggest you to try to connect through your local Wifi network instead.
Does your iPad manage to get on the internet through the connection?
Cheers,