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

138986-screen+shot+2017-05-24+at+8.13.51+am.png

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

138987-whatsapp+image+2017-05-24+at+08.16.50.jpeg

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.

Thanks!