Microsoft Acknowledges Windows 11 Update Broke File History, Optional Preview Fixes It
Microsoft has acknowledged that September 2026 Windows security update KB5124008 broke File History backups in Windows 11. An optional preview update restores backup creation and updating, though TechRadar reports some Run now and save-time synchronization issues remain.
The bug had been reported for more than two weeks before Microsoft acknowledged it, TechRadar said, even though it was a widely reported issue. File History does not see heavy use today, but it remains important for users who rely on it.
An optional September update, which is a preview of the October update, fixes the bug, according to Windows Latest. A user post on Microsoft's Learn portal confirmed that File History was working again and making backups, Windows Latest noticed. The fix does not appear to resolve every problem. The same user reported that the 'Run now' ability and synchronization of save times still had issues, according to TechRadar.
TechRadar said the remaining glitch was not caused by recent Windows 11 work and dated back to a Windows 11 update in July 2026. Because the remedy is in an optional update, TechRadar advised waiting for the October update, scheduled for October 13, and installing that instead. In the meantime, users can keep backups manually or on OneDrive, the report said.
Windows 11 bugs have continued to affect users through 2026 and in previous years, particularly with the 24H2 release, TechRadar said. Some users have called for delaying or disabling updates. One Reddit user cited by TechRadar said people should let others test bugs for a few months before updating, while another commenter asked whether there is a core Windows 11 feature that has not been broken at least twice since release.