Try this fix from Microsoft tech - worked for me...
Go here: https://www.microsoft.com/en-us/software-download/windows10
Click on the second link 'Download tool now'. Run the Media Creation Tool on...

Exact same error on two PC's I have here, both running 10 Pro. First time I've tried to use System Restore since both were updated with the Anniversary Update. Worked fine prior to 1607, so don't...