Hi all, I had the same issues as @rainerle. I just got my AD2 and DD to work and thought I should make an account to describe my system state:
OSX 10.14.6
Waveforms 3.15.2 (latest beta linked above)
They key change to get it to work was I did NOT delete the FTDI driver like the popup instructs. After rebooting, everything is good.