ctrl+zが効かない

```
Trying to update the managed reference registry with invalid propertyPath(likely caused by a missing reference instance)'managedReferences[1960223706314440857].position.y', with value '560'
UnityEditor.EditorApplication:Internal_CallGlobalEventHandler ()
```

```
The serialized array of [SerializeReference] objects is missing entry for Refid 1960223706314440987
```