Additive Loading scene causes (4.6f1)

I am getting this error message when loading a scene which has references to prefabs containing InputFields. I am fairly certain this is nothing to do with my use of prefabs, since it worked fine without error on b20.

Code (csharp):

1. Setting the parent of a transform which resides in a prefab is disabled to prevent data corruption.
2. UnityEngine.Transform:SetParent(Transform, Boolean)
3. UnityEngine.Transform:SetParent(Transform) (at C:\BuildAgent\work\d63dfc6385190b60\artifacts\EditorGenerated\UnityEngineTransform.cs:136)
4. UnityEngine.UI.InputField:UpdateGeometry() (at C:\BuildAgent\work\d63dfc6385190b60\Extensions\guisystem\guisystem\UI\Core\InputField.cs:1488)
5. UnityEngine.UI.InputField:Rebuild(CanvasUpdate) (at C:\BuildAgent\work\d63dfc6385190b60\Extensions\guisystem\guisystem\UI\Core\InputField.cs:1469)
6. UnityEngine.UI.CanvasUpdateRegistry:PerformUpdate() (at C:\BuildAgent\work\d63dfc6385190b60\Extensions\guisystem\guisystem\UI\Core\CanvasUpdateRegistry.cs:103)
7. UnityEngine.Canvas:SendWillRenderCanvases() (at C:\BuildAgent\work\d63dfc6385190b60\artifacts\EditorGenerated\UICanvasBindings.cs:152)

- It doesn't happen when loading the scene directly in the editor, only when loading additively into an existing scene. I haven't tested loading non-additively yet.

- After this error occurs, Input Carat objects are placed into the scene and don't disappear when play mode is exited.

- Modifying the scene to remove the references to the prefabs stops the error and input carat objects from appearing.

- The error appears even if the object that uses the prefab is disabled, or the prefab reference is not used anywhere.

- The error appears even if the prefabs are never instantiated

 

Can you make a bug report with repro project and description of repro steps? Thanks.

 

Oh, damn, I can't believe I missed that! And it's on page 1 of this board, too.