NullReferenceException is thrown on "Shift+1" key pressing in the Skinning Editor to "Reset Pose" of character under "Sprite Editor" Window, refer the attached video

Steps to repro:
1. Create a new project
2. Window > Package Manager > 2D Animation(4.0.0) > Install
3. Import Sample Project Under 2D Animation Package
4. Asset > Unity Technology > 2D Animation > Sample > Sprite > Boris
5. Open Sprite Editor > Skinning Editor
6. Press "Shift+1"

Actual Result:
NullReferenceException is thrown on Pressing "Shift+1" key for "Reset Pose" of Character

Expected Result:
Character Pose get Reset without any exception is thrown

Reproducible on:
2020.1.0a14, 2019.3.0f1

Note: 2D animation package 3.0.2 is introduced in unity 2019.3.0a10

Package Found version: 4.0.0, 3.0.8, 3.0.5, 3.0.2

Environment:
Windows 10 & macOS 10.14

Stack trace:
NullReferenceException: Object reference not set to an instance of an object
UnityEditor.U2D.Animation.SkinningModule.DisablePoseModeKey (UnityEditor.ShortcutManagement.ShortcutArguments args) (at Library/PackageCache/com.unity.2d.animation@4.0.0/Editor/SkinningModule/SkinningModuleView.cs:42)
UnityEditor.ShortcutManagement.Trigger.HandleKeyEvent (UnityEngine.Event evt, UnityEditor.ShortcutManagement.IContextManager contextManager) (at <f77adbe680d5435ab56e2403863ec057>:0)
UnityEditor.ShortcutManagement.ShortcutController.HandleKeyEvent (UnityEngine.Event evt) (at <f77adbe680d5435ab56e2403863ec057>:0)
UnityEditor.ShortcutManagement.ShortcutIntegration.EventHandler () (at <f77adbe680d5435ab56e2403863ec057>:0)
UnityEditor.EditorApplication.Internal_CallGlobalEventHandler () (at <f77adbe680d5435ab56e2403863ec057>:0)