Hi,
I'd suggest to add path to appropriate driver .dll (e.g. ControlCAN.dll) and test the connection. In my case I also do not see any driver found but FreeMASTER works just fine with my ZLG compatible device.
Note:
make sure there is no other application using ZLG device at the moment you are trying co use it in FreeMASTER.

hope it helps.
Stan.