Reproduced on 4.2 and 4.3
See user's description, but not crashing when uncomment 2B part in EffectController.cs

How to reproduce:

1. Open attached project
2. Open scene Scenes/Main.scene
- Scene contains a sphere which orbits around a centre axis when the scene is played
3. Open the script Scripts/EffectController.cs
- Script has a few commented out sections all marked using comments:
- 1A - Calls Blit(frameBuffer, null, blitMaterial) in OnPostRender() - this results in nothing being shown on screen
- 1B - Calls Blit(frameBuffer, destination, blitMaterial) in OnRenderImage() - this also results in nothing being shown. There is also a commented out Blit with 'null' instead of 'destination', which results in the same
- 2A - Results in black screen unless the refCam.targetTexture = null; line is uncommented. Then it shows the sphere orbiting, but with a green filter on screen
- 2B - Blit(destination) results in the rendered image be a screenshot of the Scene view, Blit(null) results in green artifacting