User does not have read rights on OS File Resource imported for Scripted OS Install. The OS File Resource is seen as Deployment > OS Files in the Console.
Error: Unexpected exception creating new task schedule. The current user does not have required permission to 'read' to load item: <Guid of OS Install>
Scripted OS Files window in the Console in Deployment > OS Files:
8.5 RU4 and on
The user needed Read rights on the OS File Resource. This is located under All Resources > Software Component > OS File Resource. Use the blue + sign to add this item if needed.