When you are editing a App Layer, the packaging machine may boot to a black screen with a spinning circle on reboot.  This would affect App Layers, not Platform or OS layers.

The App Layering driver is having a problem with actions occurring on Files and Folders under C:\Windows\Winsxs\Temp.  It is not clear where these files came from or why something is trying to modify them when editing App Layers.  Versioning the OS layer to allow the OS to complete any pending tasks does not seem to resolve the issue.

Deleting the file and folders under C:\Windows\Winsxs\Temp in the OS layer seems to resolve the issue.  

When you are editing an App Layer, the package machine may boot to a black screen with a spinning circle on reboot.