[.] Once we have confirmation that there is no further impact we will move towards an official re-release of the Windows 10 October 2018 Update.
"While we can not guarantee the outcome of any file recovery work, if you have manually checked for updates and believe you have an issue with missing files, please minimise your use of the affected device and contact us directly", Cable said, tendering an apology "for any impact these issues may have had on any of our customers".
When users upgraded to Windows 10 1809, the software update dutifully deleted the folders in the original location, including the files they contained, Cable said.
While Microsoft has apparently fixed the worrying file deletion bug we've seen with the Windows 10 October 2018 Update - at least for testers at the moment, anyway - there's another issue those who have installed the upgrade should be aware of, namely that a change made to Disk Cleanup now means that it can potentially clear out files in the Downloads folder.
Microsoft confirms that it has investigated the issue fully so that the described issues won't occur anymore.
Microsoft discovered in its investigation that the issue impacted one one-hundredth of one percent of version 1809 installs. KFR is the process of redirecting the known folders of Windows including Desktop, Documents, Pictures, Screenshots, Videos, Camera Roll, etc. from the default folder location, c:\users\username\, to a new folder location.
According to Cable, the root of the issue was new code that Microsoft implemented to remove duplicated known folders when Known Folder Redirection (KFR) is enabled. For example, an empty copy of the original C:\Users\Name\Downloads folder appeared.
Furthermore, an early buggy version of the OneDrive client with autosave turned on didn't move files in users Documents and Pictures folders from the old location to the new one.
Correcting the issue required three specific fixes, each of which you can read about in more detail in Microsoft's blog post. The company also states it will provide an update as soon as a fixed version of the Windows 10 October 2018 will be rolled out again.
The feature is built-in to the Windows operating system. They should have only deleted the folders if they were actually empty!
Microsoft has also changed the workaround text on its website.
He added that Microsoft Support and our retail stores customer service personnel are available at no charge to help customers.