Navmesh breaks after hitting build or build>paths after upgrading to 4.7.2

Navmesh breaks and repeats pattern from individual landscape section when a project is updated to 4.7.2 and then build or build paths is pressed.

1. Download project at:

[Link Removed]

2. Unzip and open project Anna 4.7
3. Press P to show navmesh
4. Press Build

Data corruption importing landscape to 4.7