When "Show Bounds" Enabled or Disabled earlier from Particle Effect Panel in the scene view and Undo operation is performed then it causes the editor to throw MissingReferenceException, refer the attached video.

Steps to repro:
1. Create a new project.
2. Hierarchy > Create > Effect > Particle System
3. Scene View > Particle Effect panel > Show Bounds, Show Only Selected > Enable OR Disable
4. Edit > Undo Create Particle System

Actual Result:
MissingReferenceException is thrown on performing Undo operation when Show Bounds Enabled or Disabled earlier from Particle Effect Panel

Expected Result:
Undo operation is performed gracefully with Particle System GameObject

Occurring on:
2020.2.0a14, 2020.1.0b12, 2020.1.0b2

Working fine in:
2020.1.0b1, 2019.3.15f1

Environment:
Occurs only on Windows 10

Stack trace:
MissingReferenceException: The object of type 'ParticleSystem' has been destroyed but you are still trying to access it.
Your script should either check if it is null or you should not destroy the object.
UnityEditor.ParticleEffectUI.PlayBackInfoGUI (System.Boolean isPlayMode) (at <feb76e495af340bfbdc89fc2ad1b8ae4>:0)
UnityEditor.ParticleEffectUI.PlayStopGUI () (at <feb76e495af340bfbdc89fc2ad1b8ae4>:0)
UnityEditor.ParticleEffectUI.SceneViewGUICallback (UnityEngine.Object target, UnityEditor.SceneView sceneView) (at <feb76e495af340bfbdc89fc2ad1b8ae4>:0)
UnityEditor.SceneViewOverlay.WindowTrampoline (System.Int32 id) (at <feb76e495af340bfbdc89fc2ad1b8ae4>:0)
UnityEngine.GUILayout+LayoutedWindow.DoWindow (System.Int32 windowID) (at <9e3b197786024cdcb531b292c5998102>:0)
UnityEngine.GUI.CallWindowDelegate (UnityEngine.GUI+WindowFunction func, System.Int32 id, System.Int32 instanceID, UnityEngine.GUISkin _skin, System.Int32 forceRect, System.Single width, System.Single height, UnityEngine.GUIStyle style) (at <9e3b197786024cdcb531b292c5998102>:0)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&)