Microsoft Explains Why Windows 10’s October 2018 Update Was Deleting People’s Files

Microsoft Explains Why Windows 10’s October 2018 Update Was Deleting People’s Files

Microsoft Explains Why Windows 10’s October 2018 Update Was Deleting People’s Files

Last week we paused the rollout of the Windows 10 October 2018 Update (version 1809) for all users as we investigated isolated reports of users missing files after updating.

The users who got hit with the file loss typically had selected "Check for Updates" within the Settings area of Windows 10, which immediately initiated a delivery of new updates to their systems, including an installation of version 1809.

As Microsoft's John Cable explains in a post on Microsoft's Windows Blog, the problem was with the "Known Folder Redirection" feature. But we're shocked that Microsoft messed up in the first place.

According to Cable, the bug was related to how Windows handled a feature called Known Folder Redirection (KFR), in which "known folders of Windows including Desktop, Documents, Pictures, Screenshots, Videos, Camera Roll, etc." are reassigned to different locations on a machine's hard drive.

Since the Windows 10 April Update, KFR has left empty duplicate Known Folders after the move, which version 1809 meant to clean up.

While discovering that an update has deleted files is annoying in and of itself, even more frustrating is that this was a known issue in one of the earlier test builds in the Insider program.

Windows 10 October 2018 Update was officially released at Microsoft's Surface hardware event last week and the upgrade promises to deliver a ton of new functionality.

It's unfortunate that the only time Microsoft chose to skip Release Preview testing, a major issue most apparent when upgrading from the old update to the new one was a serious problem users could face.

The feature is built-in to the Windows operating system. Specifically, the update introduced code that removed empty, duplicate known folders.

We have fully investigated these issues and developed solutions that resolve all three of these scenarios, so the "original" old folder location and its contents remain intact.
Hopefully, this will teach Microsoft not to skip its Release Preview testing in the future. Microsoft is making its Microsoft Support and retail store customer service personnel available to help customers recover data lost in the flawed original update at no cost. It also released some other small updates: a fix to a bug that deleted user profiles due to incorrect time calculation if the "Delete user profiles older than a specified number of day" group policy is enabled; and security updates for everything from the Windows Kernel and Windows Media Player.

Related news