Windows September security patches disrupt File History backup operations
Microsoft has acknowledged that the September 2026 security updates can prevent the File History feature from creating or updating backups on some Windows systems. Affected users may see crash events in Event Viewer referencing FileHistory.exe and KERNELBASE.dll, along with misleading 'Reconnect your drive' prompts and stale backup timestamps. The company has not yet provided a permanent fix, but it is investigating the issue alongside other problems caused by this month's updates.
The September 2026 cumulative updates have already triggered a cascade of problems, including Remote Desktop Services failures, Hyper-V issues, and USB audio glitches, some of which required out-of-band emergency fixes. Microsoft’s acknowledgment of File History disruptions adds another layer, with crash logs pointing to FileHistory.exe and KERNELBASE.dll. The feature, which automatically saves copies of user folders to external drives or network locations, is essential for recovering accidentally deleted or corrupted files. Affected systems may show misleading “Reconnect your drive” prompts and fail to update backup timestamps, leaving users without fresh restore points. Microsoft has not issued a permanent solution, only confirming it is investigating alongside other lingering audio and login issues.
This bug could undermine trust in Windows’ built-in data protection, especially for home users and small businesses relying on File History for offline backups. Those who depend on automatic snapshots may face data loss windows if they assume backups are running. While cloud alternatives exist, the disruption may prompt some to seek third-party tools, but for now, affected users must manually verify backup integrity and wait for Microsoft’s fix.