- Drag and Drop the main camera from a scene into the Project Browser to turn it into a prefab
- Create a new RenderTexture and assign it to the Target Texture field in the Camera component of the camera prefab
- Delete the Main Camera from the scene
- Delete the prefab of the Main Camera that you created in the first step
- Press Undo (Ctrl Z) 2-3 times

Result: "Dereferencing NULL PPtr!" is printed in the console - no file or line number

Actual: Main Camera object gets recreated in the Hierarchy. No errors are displayed.

Regression compared to Unity 4.3.0a3 (ab429cd6e2f7)