Windows 10 build 17763.17 heads to the Slow and Release Preview rings with fix for deleted files issue

Microsoft has just announced that it has fixed a rare issue that caused some personal files to be erased when installing the Windows 10 October 2018 update. The company is testing the fix with Windows Insiders on the Slow and Release Preview rings today, whom can both download the Windows 10 October 2018 Update Build 17763.17.

John Cable, Director of Program Management, Windows Servicing and Delivery penned a long blog post to explain what went wrong during testing. “While the reports of actual data loss are few (one one-hundredth of one percent of version 1809 installs), any data loss is serious,” the exec wrote.

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. You can find Cable’s detailed explanation below:

Prior to re-releasing the October 2018 Update our engineering investigation determined that a very small number of users lost files during the October 2018 Update.  This occurred if Known Folder Redirection (KFR) had been previously enabled, but files remain in the original “old” folder location vs being moved to the new, redirected location.  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. In previous feedback from the Windows 10 April 2018 Update, users with KFR reported an extra, empty copy of Known Folders on their device.  Based on feedback from users, we introduced code in the October 2018 Update to remove these empty, duplicate known folders.  That change, combined with another change to the update construction sequence, resulted in the deletion of the original “old” folder locations and their content, leaving only the new “active” folder intact.

The good news is that Microsoft has seemingly fixed the issue in Windows 10 Build 17763.17, and now the original old folder location and all the personal documents it contained should remain intact when you install the October 2018 update. “We will carefully study the results, feedback, and diagnostic data from our Insiders before taking additional steps towards re-releasing more broadly,” Cable said.

As the October 2018 update was only made available for customers who actively checked for updates in Windows Update, the company says that “the number of customers taking the October 2018 update was limited.” Still, if you lost any personal data after proceeding, be aware that Microsoft will offer free customer support online and at its retail stores.

“We are committed to learning from this experience and improving our processes and notification systems to help ensure our customers have a positive experience with our update process,” Cable said today. The company will also revamp its Feedback Hub to let users indicate the severity of a bug when filing user feedback, which should hopefully help to avoid serious bug being ignored in the future.