October 2018 Update deleted some user's files
https://www.bleepingcomputer.com/news/microsoft/known-problems-and-fixes-for-october-2018-windows-10-updates/
It has been almost two weeks since Microsoft released updates for Windows 10 as part of their October 2018 Patch Tuesday and what a long two weeks it has been. These updates could have been Microsoft's worst Patch Tuesday in a long time with numerous bugs that not only made Windows 10 PCs unusable, but for some resulted in the loss of personal files.
It got so bad that Microsoft had to pull the Windows 10 October 2018 Update in order to give themselves times to properly figure out what was causing the problems, fix them, and then test the updated build with Windows Insiders.