Windows 10 and Windows 11 users have recently encountered a new issue: after installing the September security updates, the "File History" feature stops performing backups. Event logs record application crashes referencing FileHistory.exe and KERNELBASE.dll, but Windows only registers them as general errors without explicitly linking them to the backup functionality.
Symptoms may appear contradictory:
Even if external USB storage or network storage is connected and functioning properly, prompts to "Reconnect drive" will repeatedly appear.
The "Last backup" date in the Control Panel no longer updates.
When attempting to restore files modified after the update, version history is not displayed; instead, a message states "Previous versions are not available."
This issue affects the following versions:
Windows 11 versions 23H2 to 26H1
Windows 10 versions 22H2 and 21H2, as well as Enterprise LTSC 2016 and 2019
Microsoft has released an emergency Windows 11 update to fix sound and Remote Desktop issues. This malfunction is related to the following security updates: KB5124012, KB5124008, KB5122880, KB5122878, KB5122876, and KB5123099. Microsoft stated that Windows Server versions are not affected.
In the same September update batch, Microsoft also fixed two zero-day vulnerabilities that were being actively exploited and dozens of other critical vulnerabilities. Therefore, neither Microsoft nor security experts recommend uninstalling the patch to bypass this bug. No temporary workaround has been officially provided at this time.
Before a fix patch is released, users and administrators relying on "File History" are advised to take the following measures:
Manually check backup logs and timestamps in the Control Panel.
Do not assume that a connected drive means the backup was successful.
Temporarily use alternative solutions: back up via OneDrive or use third-party software to create disk images.
Microsoft stated that the fix will be included in a future update, but no specific timeline has been announced.