It seems it's no more compatible out of the box with Unity 5.6.Probably you guys are already working on the update for this.
You got it! Unity 5.6 support is in the works and will be released soon. If you're feeling adventurous, you can use the develop branch in the Unity Modules GitHub: https://github.com/leapmotion/UnityModules
Thanks!! Well, meanwhile, I'm adjusting the obsolete parts of the scripts myself, to keep project going. Awaiting the release! Nice work