Microsoft has re-released the October 2018 update to Windows 10 after (hopefully) fixing the bug which deleted some customers vital files.
The October 2018 update problem was caused by changes to Known Folder Redirection or KFR which we’ll explain below.
Windows 10 October 2018 update – take two
The Windows 10 October 2018 update is now available again after Microsoft temporarily withdrew it.
The update is currently ‘on request’. You won’t get the update unless explicitly asked for. After a few weeks, Microsoft will start pushing the update out to all Windows 10 users. See Windows 10 for Microsoft Office users for advice on delaying the pushed update until you’re ready, even with Win10 Home edition.
Anyone affected by the update bug can contact Microsoft for free support, though it’s not clear what Microsoft can do without a backup of the deleted files.
What to do now
Our regular advice on major updates still applies: Wait.
The new Clipboard in the October 2018 update is very useful but there’s no rush to update. Either wait until Microsoft pushes the update to you or ask for it when you’re ready.
Before any update, always, always, do a full backup. The people caught by the Microsoft’s update must be wishing they did.
Again, all the details are just part of Windows 10 for Microsoft Office users.
Known Folder and Known Folder Redirection
Windows has ‘Known Folders’ for things like Documents, Downloads, Music etc.
Normally these are links to C:\Users\<username>\ folders but can be redirected to another location easily. Right-click choose Properties | Location to see the current Known Folder location or move it to another place. The Move … button starts Known Folder Redirection (KFR) which is the source of the update problem.
Moving a Known Folder isn’t that unusual. If you have a fast but small SSD drive as C:, you might move larger Known Folders to Drive D. It’s a common tactic for people with a small drive C but larger capacity D or E drives.
It’s also a tactic for OneDrive users to redirect a computer Known Folder to the OneDrive synced location. For example, redirect the users Documents Known Folder to their OneDrive Documents folder. In that way, they have a single Documents folder synced with OneDrive.
KFR should, repeat should, move all files from the old folder (say C:\users\me\Documents\ ) to the new location ( say D:\Documents ) and change Windows registry to point to the new Known Folder location.
But some customers were reporting have two Known Folders. The old location C:\users\me\ had an empty copy of the Known Folder. Microsoft attempted to tidy up this duplicate Known Folder but, seemingly, didn’t allow for the possibility that the old KF might have files.
In practice the old folder can still have files in it. Some programs don’t use Known Folders can go to the c:\users\ location. Or the user themselves might save files there manually rather than use the regular Explorer links.
In tidying up the Known Folder duplicates, the original October 2018 update removed any files in the old Known Folder. Because that old Known Folder was sometimes synced to OneDrive, the files were deleted from cloud storage as well.
There’s a refreshingly detailed post on the October 2018 update problem and fix. It’s nice to see that Microsoft is prepared to be more open with paying customers about problems. If only they’d do it on a regular basis and not just as part of PR damage control.