The corrupted files I saw only occurred on one client and I reverted back to original situation using Paragon image restore after spending too much time trying to fix the problem.
So unfortunately I can’t give you now any further specific data on those corrupted files.
I definitely used Windows Repair from Tweaking, and I am aware of Reimage, which I am a bit suspicious of.
The exe I used is called ‘windows_repair.exe’ and the file size is around 29 MB. Dated 6 November 2016.
I agree also it is probably impossible to have reverted back a version of W10. I had assumed the update had completed as I did not see a message that the update had reverted, which I usually note on the feature update failure.
I repaired the second of the 3 problem computers with Tweaking repair, and I did not see anything similar to the first issue. I do know for sure the update did not complete on this one, so it seems clearer the windows update itself did not reverse completely back to normal.
I will probably only get physical access to the third computer next week, as it is far from where I am now.
if the latest update does not fix the issue , I will run Tweaking Repair again and see if anything similar happens, but I doubt to see the same thing again!