Windows 10 October 2018 Update bug can lead to data loss in My Documents folder

The upgrade to Windows 10 October 2018 Update turned into a nightmare for some users as a serious bug can cause massive data loss. Dozens of reports hit the web of users who lost their entire "My Documents" folder after upgrading to the latest version of Windows 10.

Users complain that after installing Windows 10 October 2018 Update, all files are gone from the "C:UsersPublicDocuments" and "C:UsersDocuments" and folders. Rolling back to the previous version of Windows is not a solution as the files aren't present in "C:Windows.old"

At the moment, Microsoft hasn't offered a comment yet. Interestingly, MyCE reports this bug was already mentioned over three months ago in the Windows 10 Insider Feedback Hub:

Interesting is that the bug was already reported to Microsoft more than 3 months ago. In the Windows 10 Insider Feedback Hub a user writes, “I foolishly decided to enroll in the Windows Insider Program. Not wanting to put everything into the UsersUSERNAMEOneDriveDocuments folder, I had created my own Documents folder under UsersUSERNAMEDocuments. After the update, my Documents folder had been overwritten with a new Documents folder, complete with custom icon. All contents were gone.”

ExtremeTech speculates there may be a OneDrive-related bug:

There’s no word for why some users are seeing massive data loss, or what settings or level of OneDrive implementation is leading to these issues. This is pure speculation on my part, but based on what users are reporting, it sounds as if files that ought to be backed up to OneDrive (possibly as part of the new features Microsoft has rolled out around that capability) are instead being deleted. But they aren’t being moved to the Windows.old directory first, and they aren’t being backed up to another location or even simply dumped in the Recycle Bin.

Until this is cleared out, it's probably best to delay the upgrade to Windows 10 October 2018 Update until further notice.