Steps to reproduce:
1. Download the .unitypackage (attached in one of the letters)
2. Import it to an empty project
3. Open testScene
4. In scene view, observe that the cube

Expected result: cube is purple
Actual result: cube is gray or black even though in camera preview it's seen as purple

Note:
-Reproduces when a scene has 2 or more cameras when none of them are tagged as "MainCamera"
-Take careful note of 'Not Saved' Render textures in the detailed memory profiler in unity, it reveals that certain deferred textures have reverted to not initialised

Reproduced on: 2017.3.0p2, 2018.1.0b6, 2018.2.0a1 (342a6a4b3328)