How to reproduce:
1. Open the attached project("test-failure.zip")
2. In the Test Runner window click Run All
3. Quickly minimize Unity

Expected results: No exception is thrown
Actual results: ArgumentException: The scene is not loaded is thrown

Reproducible with: 2019.4.14f1, 2020.1.13f1, 2020.2.0b11, 2021.1.0a5
Couldn't test with: 2018.4.29f1 (Couldn't downgrade)

First lines of the Exception thrown:
ArgumentException: The scene is not loaded.
UnityEngine.SceneManagement.Scene.GetRootGameObjects (System.Collections.Generic.List`1[T] rootGameObjects) (at <052502435982472d92da7f939c7f8164>:0)
UnityEditor.SceneVisibilityManager.AreAllDescendantsHidden (UnityEngine.SceneManagement.Scene scene) (at <3037c1046402403280ab8b0782ca806f>:0)
UnityEditor.SceneVisibilityManager.GetSceneVisibilityState (UnityEngine.SceneManagement.Scene scene) (at <3037c1046402403280ab8b0782ca806f>:0)
UnityEditor.SceneVisibilityHierarchyGUI.DrawSceneItemVisibility (UnityEngine.Rect rect, UnityEngine.SceneManagement.Scene scene, System.Boolean isItemHovered, System.Boolean isIconHovered) (at <3037c1046402403280ab8b0782ca806f>:0)