Unity 2018.3.0b11 Having a problem with prefab creation, where SaveAsPrefabAsset() is successful but returns null. GetCorrespondingObjectFromSource() returns null. AssetDatabase.LoadAssetAtPath() returns null. However, the prefab is none the less successfully created. The problem is that I can't create the prefab, and then modify it with AddObjectToAsset() to save meshes, etc. to it. Posing a difficult problem in our asset pipeline, and seems to me it must be a bug. I'm making the call inside of PostProcessAllAssets(), and it seems the saved prefab is not being 'imported' until after my code exits, but it's too late then to update it properly.