Reproduction steps:
1. Open the attached project "ddxshader.zip";
2. Open the SampleScene.unity;
3. Observe the Sphere object in the Scene view.

Expected results: the object has DDX shader which gives the light grey color to it;
Actual results: the object is rendered in black without any color values.

Reproduced on: 2018.1.0a1, 2018.1.0b12, 2018.2.0a5.
Not reproduced on: 2017.1.3p2, 2017.2.1p4, 2017.3.2f1.

Fixed on: 2018.1.3f1, 2018.2.0b5, 2018.3.0a1.