- Open AngryBots scene and select the Environment(static) parent object in the Hierarchy
- Disable it in the Inspector (uncheck the active box)

Console reports the following error: "Failed to create Undo for action Deactivate Environment(static), because the action is too large. Clearing undo buffer
UnityEditor.DockArea:OnGUI()"

Not a regression, compared to 4.0, at least.