How to reproduce:
1. Open the attached 'EditorSceneManager.sceneClosing.zip' project using the EnvIronman VM (optional) (more information in Edit)
2. Load 'SampleScene' scene
3. Load 'AddiitonalTestScene' by dragging it into the Hierarchy window from the Project window
4. In the Hierarchy window right-click on the 'AddiitonalTestScene' and select 'Unload Scene'
5. Observe the Console window
6. In the Hierarchy window right-click on the 'AddiitonalTestScene' and select 'Load Scene'
7. Observe the Scene window

Expected result: the cube is initialized at (0, 10, 0) position and no exception should be thrown
Actual result: the cube is initialized at its original position and an ArgumentException is thrown

Reproducible with: 2019.2.0a7, 2019.2.3f1, 2019.3.0b1, 2020.1.0a1
Not reproducible with: 2017.4.32f1, 2018.4.7f1, 2019.2.0a6

Thrown exception:
ArgumentException: The scene is not loaded.
UnityEngine.SceneManagement.Scene.GetRootGameObjects (System.Collections.Generic.List`1[T] rootGameObjects) (at C:/buildslave/unity/build/Runtime/Export/SceneManager/Scene.cs:97)