I have the same problem. I have installed ANTware II but it does not seem to see the nRF 51 Nordic PCA10031 dongle.
The Device Panel is empty, just a large + sign.
The dongle is not in use in other applications.
When I start Nordic nRFgo Studio it can see the dongle, shows it empty (no application, no Softdevice).
If Studio can see it why can't ANTware? Is there any firmware that needs to be loaded into the dongle? Where do I find it?
Thanks a lot,
Steve