Unreal Engine 4 tutorial - How to make 3D water/lava with waves/adjustments 2017

Why is tesselation not working on my Mac?

Mac Pro 2013, 64 GB ram.
Tried in 4.14 and 4.15, but no tesselation at all. What have I missed?

It should but then again it’s a mac so I wouldn’t be surprised.

Fixed in 4.15… Thanks for the tut.