LeapEventInterface missing on Mac OS

Good morning.

I’m trying to implement the LeapEventInterface in my Character Blueprint.
On 4.16 preview, running on MacOS X, the interface is missing


However running the same version on Windows I can see the interface:


I would really like to work on the Mac as my Windows machine is a little slow and not always with me.
Is there something obvious I’m missing? Or anything I can do to fix this?

Unreal Engine 4.16 Preview 3, running on MacOS X Sierra 10.12.3 has the problem.
Unfortunately I don’t have another engine version installed to check on at the moment.