Errors are thrown into console and editor crashes when light probe group is assigned to Anchor Override parameter of a Mesh Renderer

1) Download project:
http://bugs04.unity3d.com/fogfiles/1016818_g5r2io0q2gi842f8/case_1016818-PhysicalLightUnits.zip
2) Open scene `Test_Environment`
3) Create a light probe group
4) Select a mesh and assign the light probe group to `Anchor Override` parameter of a Mesh Renderer
5) Observe the assertions, editor crashes after awhile (or simply delete the MeshRenderer that has a light probe group assigned to `Anchor Override`)

Reproducible on: 2018.2.0a4, 2018.2.0a2, 2018.1.0b11, 2018.1.0b9, 2018.1.0b7, 2018.1.0b5, 2018.1.0b3, 2018.1.0b2, 2018.1.0b1, 2018.1.0a5, 2018.1.0a4.

Works fine on: 2018.1.0a3, 2018.1.0a2, 2018.1.0a1, 2017.3.f3.

Frequency:
Always.

Environment:
Occurs on Mac and Windows.