Question Reloading a Prefab scene that is not the current stage is not supported currently.

I'm getting this error when I edit one of my prefabs, but am unable to determine where it's originating as I don't specifically reload the prefab AFAIK, and there's no stack trace information for me to walk back from unity's internal code to where I may be inadvertently triggering it.

Full Error Message

Code (CSharp):

1. Reloading a Prefab scene that is not the current stage is not supported currently.
2. UnityEditor.EditorApplication:Internal_CallUpdateFunctions() (at C:/buildslave/unity/build/Editor/Mono/EditorApplication.cs:303)

It only happens to a specific duplicated prefab if prefab AutoSave is on, or when off when I manually press the small prefab save button for specific prefabs with nested prefabs within. Even weirder, is I can delete all children of the prefab and remove all attached components, but it still happens.

Unfortunately I can't share the scene, project, or asset.