When "Custom Passes"(DrawRenderersCustamPass, FullScreenRenderPass, CustomClear) are moved up or down from "CustomPassVolume" preset in the Inspector then it causes Editor to crash, refer attached video.

Sometime "NullReferenceException" has been thrown when order of "Custome Passes" in the list is changed and after deleting "CustomPassVolume" preset causes the Editor to crash.

Steps to repro:
1. Create a new project with HDRP Template
2. Hierarchy > Create > Volume > Custom Pass
3. Inspector > Custom Pass > Click on "" > DrawRenderersCustamPass and FullScreenRenderPass and CustomClear
4. Moved Custom passes Up or Down
5. Create Preset of Custom Pass Volume (Script)
6. Project > CustomPassVolume preset > Moved Custom passes Up or Down

Actual Result:
Editor crashes when the order of "Custome Passes" in the list is changed in the "CustomPassVolume" preset from Inspector

Expected Result:
Custome Passes should be moved Up or Down gracefully

Occurring in:
2020.2.0a17, 2020.2.0a15 with package version 9.0.0-preivew.33, 9.0.0-preview.13, 8.1.0

Working fine in:
2020.2.0a14, 2020.1.0b15 with package 9.0.0-preivew.33, 9.0.0-preview.13, 8.1.0

Environment:
Occurring on Windows 10 & macOS 10.15.

Stack trcae:
NullReferenceException: Object reference not set to an instance of an object
UnityEditor.PropertyEditor.Update () (at <fc44262c43cd402d975d22277bf4bb54>:0)
UnityEditor.HostView.SendUpdate () (at <fc44262c43cd402d975d22277bf4bb54>:0)
UnityEditor.EditorApplication.Internal_CallUpdateFunctions () (at <fc44262c43cd402d975d22277bf4bb54>:0)

NullReferenceException: Object reference not set to an instance of an object
UnityEditor.Editor.get_target () (at <fc44262c43cd402d975d22277bf4bb54>:0)
UnityEditor.InspectorWindowUtils.GetFirstNonImportInspectorEditor (UnityEditor.Editor[] editors) (at <fc44262c43cd402d975d22277bf4bb54>:0)
UnityEditor.PropertyEditor<>c__DisplayClass124_0.<RebuildContentsContainers>b__0 () (at <fc44262c43cd402d975d22277bf4bb54>:0)
UnityEngine.UIElements.IMGUIContainer.DoOnGUI (UnityEngine.Event evt, UnityEngine.Matrix4x4 parentTransform, UnityEngine.Rect clippingRect, System.Boolean isComputingLayout, UnityEngine.Rect layoutSize, System.Action onGUIHandler, System.Boolean canAffectFocus) (at <434515d9f4bb4f26bab9aa61f75e4922>:0)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&)