0.1.4 -> 0.2.0 のMigrationでエラー

[hitsub]

アプデ後のMigrationでEverythingを選ぶとエラーダイアログが出ました。
以後、実行毎にMigrationダイアログが出ますがEverything/PrefabOnlyどちらを選んでもエラーで止まってしまうようです。

原因が分かってないですが取り急ぎエラー内容共有です。

NullReferenceException: Object reference not set to an instance of an object
Anatawa12.AvatarOptimizer.PrefabSafeSet.EditorUtil`1+<>c__DisplayClass17_0[T].<GetElementOf>b__0 (Anatawa12.AvatarOptimizer.PrefabSafeSet.IElement`1[T] x) (at Packages/com.anatawa12.avatar-optimizer/Internal/PrefabSafeSet/Editor/EditorUtil.cs:44)
System.Linq.Enumerable.TryGetFirst[TSource] (System.Collections.Generic.IEnumerable`1[T] source, System.Func`2[T,TResult] predicate, System.Boolean& found) (at <351e49e2a5bf4fd6beabb458ce2255f3>:0)
System.Linq.Enumerable.FirstOrDefault[TSource] (System.Collections.Generic.IEnumerable`1[T] source, System.Func`2[T,TResult] predicate) (at <351e49e2a5bf4fd6beabb458ce2255f3>:0)
Anatawa12.AvatarOptimizer.PrefabSafeSet.EditorUtil`1[T].GetElementOf (T value) (at Packages/com.anatawa12.avatar-optimizer/Internal/PrefabSafeSet/Editor/EditorUtil.cs:44)
Anatawa12.AvatarOptimizer.Migration.Migration.MigrateSet[T] (System.Collections.Generic.IEnumerable`1[T] values, UnityEditor.SerializedProperty setProperty, System.Int32 nestCount, System.Func`2[T,TResult] getValue, System.Action`2[T1,T2] setValue) (at Packages/com.anatawa12.avatar-optimizer/Editor/Migration/Migration.cs:406)
Anatawa12.AvatarOptimizer.Migration.Migration.MigrateSet[T] (UnityEditor.SerializedProperty arrayProperty, UnityEditor.SerializedProperty setProperty, System.Int32 nestCount, System.Func`2[T,TResult] getValue, System.Action`2[T1,T2] setValue) (at Packages/com.anatawa12.avatar-optimizer/Editor/Migration/Migration.cs:379)
Anatawa12.AvatarOptimizer.Migration.Migration.MigrateV1ToV2 (System.Int32 nestCount, UnityEditor.SerializedObject serialized) (at Packages/com.anatawa12.avatar-optimizer/Editor/Migration/Migration.cs:307)
Anatawa12.AvatarOptimizer.Migration.Migration.MigrateComponent (Anatawa12.AvatarOptimizer.AvatarTagComponent component, System.Int32 forceVersion) (at Packages/com.anatawa12.avatar-optimizer/Editor/Migration/Migration.cs:273)
Anatawa12.AvatarOptimizer.Migration.Migration.MigratePrefabs (System.Collections.Generic.List`1[T] prefabAssets, System.Action`2[T1,T2] progressCallback, System.Int32 forceVersion) (at Packages/com.anatawa12.avatar-optimizer/Editor/Migration/Migration.cs:201)
Rethrow as Exception: Migrating Prefab Grus_Cardigan: Object reference not set to an instance of an object
Anatawa12.AvatarOptimizer.Migration.Migration.MigratePrefabs (System.Collections.Generic.List`1[T] prefabAssets, System.Action`2[T1,T2] progressCallback, System.Int32 forceVersion) (at Packages/com.anatawa12.avatar-optimizer/Editor/Migration/Migration.cs:205)
Anatawa12.AvatarOptimizer.Migration.Migration.MigrateEverything () (at Packages/com.anatawa12.avatar-optimizer/Editor/Migration/Migration.cs:142)
Anatawa12.AvatarOptimizer.Migration.Migration.DoMigrate () (at Packages/com.anatawa12.avatar-optimizer/Editor/Migration/Migration.cs:62)
Anatawa12.AvatarOptimizer.Migration.Migration.Update () (at Packages/com.anatawa12.avatar-optimizer/Editor/Migration/Migration.cs:30)
System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <eae584ce26bc40229c1b1aa476bfa589>: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 <eae584ce26bc40229c1b1aa476bfa589>:0)
System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) (at <eae584ce26bc40229c1b1aa476bfa589>:0)
System.Delegate.DynamicInvokeImpl (System.Object[] args) (at <eae584ce26bc40229c1b1aa476bfa589>:0)
System.MulticastDelegate.DynamicInvokeImpl (System.Object[] args) (at <eae584ce26bc40229c1b1aa476bfa589>:0)
System.Delegate.DynamicInvoke (System.Object[] args) (at <eae584ce26bc40229c1b1aa476bfa589>:0)
UnityEditor.EditorApplication.Internal_CallUpdateFunctions () (at <a259d3c004024353a2c217da97495055>:0)

[hitsub]

Migration.MigrateV1ToV2()において、

serialized.FindProperty(nameof(MergeSkinnedMesh.renderers)

ここでNullが混じっていると最終的にEditorUitl.GetElementOf()の引数にNullが渡されることで例外になるようです。
Prefabの作りが悪いといえばそうですが、Nullで処理が止まってしまうのはよくなさそうです。。