Microsoft Rolls Out Fix for File History Backup Bug From September Updates
Microsoft confirms a fix for a known issue that breaks the File History backup feature after users install the September 2026 security updates. File History, available through the Control Panel, automatically backs up user profile folders such as Documents, Music, Pictures, Videos, and Desktop to an external drive or network location, letting users restore accidentally deleted or damaged files from earlier points in time.
On affected systems running Windows 10 21H2 and later, Windows 10 Enterprise LTSC 2016/2019, and Windows 11 23H2 and later, users experience crashes referencing FileHistory.exe and KERNELBASE.dll in Event Viewer, along with "Reconnect your drive" alerts even when backup drives are properly connected. Other symptoms include backed-up files showing "No previous version available" and the "Last Backup" timestamp failing to update.
The fix is rolling out through Tuesday's optional cumulative updates KB5124006 and KB5124010 for Windows 11 26H1 and Windows 11 24H2/25H2, respectively. Users who skip these optional updates will receive the fix automatically with next month's Patch Tuesday updates on October 13. Microsoft recommends installing the latest update, noting it contains important improvements and resolutions.