Terrain Texture is not drawn in 5.1.2 OSX after upgrade from 5.1.1

Scene & World Building Terrain
1

Something has corrupted in my project which means it will not display the terrain texture
For me this isolated to the Mac editor, the same project loads fine on my Windows 8.1 machine.

If I zoom out you can see the texture appears

If I start a new project on the Mac and create a terrain object it works fine and the texture is displayed.
This is a 2012 Mac Mini (Macmini6,2)
i7 2.6Ghz
16 GB RAM
Intel HD 4000 Gfx
Running Yosemite 10.10.4

2

No one else having this issue?
It seems to happen when Effects from the standard assets are imported.
Happens on a fresh project, OSX Android build.
I made the video below, you can see at ~1:00 the terrain flashes pink then disappears.

This is repeatable every time.