We have paused the rollout of the Windows 10 October 2018 Update (version 1809) for all users as we investigate isolated reports of users missing some files after updating,
-Microsoft on its support site for Windows Update.

So if you have already downloaded the latest ISO from the Media Creation Tool and not installed it, DON'T. Wait for a newer version of the ISO.

See the link below:

https://www.theverge.com/2018/10/6/17944966/microsoft-windows-10-october-2018-update-documents-deleted-issues-windows-update-paused

I installed it on Oct 3 but because I automatically take a differential image every morning I was able to roll it back out.

commented: No one I know lost a file. My bet is some edge case. But all cases are now edge cases. +15

I still cannot update the last big update from last time as it says missing files or errors, this only happened after a update from windows 10, windows are blaming your machine and not them. So gave up. I’m not doing a full new installation just because of their mistakes.
I’m on the windows insider thing and they still broke my updates.

@dorey, The insider thing is for those that want to be beta testers. I'm encountering folk that don't understand the risks.

It appears the bug that caused file deletion was related to Windows 10 users who had enabled Known Folder Redirection to redirect folders like desktop, documents, pictures, and screenshots from the default location. Microsoft introduced code in its latest update to delete the empty and duplicate known folders, but it appears they weren’t always empty. Microsoft has developed fixes to address a variety of problems related to these folder moves, and these fixes are now being tested with Windows Insiders.

https://www.theverge.com/2018/10/9/17957506/microsoft-windows-10-october-2018-update-data-deletion-fix

The re-release will start with Insider program before being fully released to normal consumers.

Good to know. I relocated all my user folders to D: so that restoring an image of C wouldn't kill all my files.

Now that Microsoft has "fixed" the problems with the file deletion (oopsie), it seems the there are situations where the new and improved update can destroy zip files. Microsoft reminds me of these guys.

commented: I just learned of that yesterday. Thanks for adding this. +15