Clicking on "Auto Setup from Tips Transform" under "Two Bone IK Constraint" editor thrown ArgumentException, refer the attached video.

Steps to repro:
1. Create a new project
2. Package Manager > Animation Rigging > Install
3. Hierarchy > right-click > Create Empty
4. Inspector > Add Component >Animation Rigging >Two Bone IL Constraint > Add
5. Hierarchy > Empty Object > Inspector >Two Bone IL Constraint > Auto Setup from Tips Transform> Click

Actual Result:
ArgumentException error is thrown on Clicking "Auto Setup from Tips Transform" under "Two Bone IK Constraint".

Expected Result:
No error in the Console

Occurring on:
2020.2.0a18, 2020.1.0b16 with Package Version 1.0.2, 0.3.3-preview, 0.3.2-preview,
2020.1.0a1 with Package Version 0.3.2-preview

Note: "Auto Setup from Tips Transform" intruded in Package Version 0.3.2-preview

Environment:
Occurring on Windows 10 & Mac 10.15.

Stack trace:
ArgumentNullException: Value cannot be null.
Parameter name: parent
UnityEditor.Animations.Rigging.TwoBoneIKConstraintEditor.TwoBoneIKAutoSetup (UnityEditor.MenuCommand command) (at library/packagecache/com.unity.animation.rigging@1.0.2/editor/animationrig/constraints/twoboneikconstrainteditor.cs:118)