im trying to use VuforiaVirtualButtonToPlaymaker, but there is a error, how can do?
Assets/PlayMaker Vuforia/Actions/VuforiaVirtualButtonToPlaymaker.cs(56,38): error CS0246: The type or namespace name `VirtualButtonAbstractBehaviour' could not be found. Are you missing `Vuforia' using directive?
im using unity 2018 and vuforia 1.9
