Microsoft fixes bug that broke Windows File History backup feature
Microsoft fixed a September update bug that stopped File History backups on Windows 10 and 11.
Microsoft said September 2026 security updates broke File History on Windows 10 21H2 and later, Windows 10 Enterprise LTSC 2016 and 2019, and Windows 11 23H2 and later. Affected systems can crash FileHistory.exe against KERNELBASE.dll, show Reconnect your drive alerts, and fail to create or update backups. Optional updates KB5124006 for Windows 11 26H1 and KB5124010 for Windows 11 24H2 and 25H2 fix the issue. Devices that skip the optional updates receive the fix on October 13 Patch Tuesday.
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