Steps to reproduce:
1. Open users attached project.
2. In project view click on "parent 3" prefab.
3. In toolbar press play button.
4. In console appears "Incorrect call to OnStateEnter" line.
--- This line is written in "testsmb" script which is attached to "test Animator Controller" animator controller which is attached to "Child" object.

Expected result: Console window shows nothing because "parent 3" prefab isn't instantiated.
Actual results: "StateMachineBehavior" instantiated and executes script even though it doesn't exist in hierarchy window.

Reproduced in: 5.4.21b , 5.3.5f1 , 5.3.4f1, 5.0.3f2.