[2D] [AnimV2] Two error messages appear in Console when deleting all vertices from a sprite that was rigged with bones, geometry, and weights

Steps to Repro:
1. open attached project and select Fei_Cel.psb
2. open the skinning editor and select an arm or a leg (arms and legs are already rigged)
3. select Edit Geometry and delete all the vertices
4. click on Apply

The following two error messages appear in the console:

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Assertion failed
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)

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Exception: Bake error: invalid SpriteSkin
UnityEngine.Experimental.U2D.Animation.SpriteSkinUtility.Bake (UnityEngine.Experimental.U2D.Animation.SpriteSkin spriteSkin) (at Library/PackageCache/com.unity.2d.animation@2.0.0-preview.6/Runtime/SpriteSkinUtility.cs:209)
UnityEngine.Experimental.U2D.Animation.SpriteSkinUtility.CalculateBounds (UnityEngine.Experimental.U2D.Animation.SpriteSkin spriteSkin) (at Library/PackageCache/com.unity.2d.animation@2.0.0-preview.6/Runtime/SpriteSkinUtility.cs:238)
UnityEditor.Experimental.U2D.PSD.PSDImporter.PostProcessPrefab (UnityEngine.GameObject go) (at Library/PackageCache/com.unity.2d.psdimporter@1.0.0-preview.5/Editor/PSDImporter.cs:1061)
UnityEditor.Experimental.U2D.PSD.PSDImporter.UnityEditor.Experimental.U2D.Animation.IAnimationAssetPostProcess.OnAfterPostProcess () (at Library/PackageCache/com.unity.2d.psdimporter@1.0.0-preview.5/Editor/PSDImporter.cs:1042)
UnityEditor.Experimental.U2D.Animation.SpritePostProcess.OnPostprocessAllAssets (System.String[] importedAssets, System.String[] deletedAssets, System.String[] movedAssets, System.String[] movedFromAssetPaths) (at Library/PackageCache/com.unity.2d.animation@2.0.0-preview.6/Editor/SpritePostProcess.cs:38)
System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
UnityEditor.AssetPostprocessingInternal.PostprocessAllAssets (System.String[] importedAssets, System.String[] addedAssets, System.String[] deletedAssets, System.String[] movedAssets, System.String[] movedFromPathAssets) (at /Users/builduser/buildslave/unity/build/Editor/Mono/AssetPostprocessor.cs:141)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)