Microsoft has stopped distributing the version 1809 update to Windows 10, otherwise known as the Windows 10 October 2018 Update, due to several reports of the update deleting files from the Documents and Pictures folders.
Microsoft lists the version 1809 update rollout as "paused" on its official Windows 10 update history page . All distributions of Windows 10 that were updated to version 1809 (including Enterprise and IoT) are potentially impacted.
As shared by Rafael Rivera on Twitter, users on Microsoft's Feedback Hub had posted about the data loss issue as far back as three months before the version 1809 update released. Rivera also notes that these reports weren't enough for Microsoft to fix the issue before making the update available to the public because of low upvote records causing the reports to get "buried in the noise."
Peter Bright at Ars Techinca notes that Microsoft did not release Windows 10 version 1809 to the Release Preview update channel before making it available to all stable channel users via Windows Update, which could have been a vital step to preventing this issue from being as widespread as it currently is.