A string of problems plaguing Microsoft’s September 2026 security updates has struck again, this time affecting the built-in File History backup feature in Windows. The feature, designed to automatically save copies of files to an external hard drive or network storage location, may stop working on some systems after installing the latest patches.
File History is a crucial component for many users, as it allows them to recover accidentally deleted or damaged files using older versions from hours, days, or weeks ago. However, according to a service alert seen by CyberNews.work and first spotted by Microsoft MVP Susan Bradley, affected customers may be unable to create or update backups after installing the September updates. The issue is not limited to just one specific version of Windows, with multiple releases impacted, including Windows 10 21H2 and later, as well as Windows 11 23H2 and later.
Users may experience a range of symptoms, including application crash events in Event Viewer referencing FileHistory.exe and KERNELBASE.dll. Additionally, Windows might incorrectly display “Reconnect your drive” messages even when compatible backup drives are connected and working properly. In some cases, the “Last Backup” timestamp may not update, and previously backed-up files may show “No previous version available.”
Microsoft’s list of affected updates includes several cumulative patches for Windows 11 and 10, including KB5124012, KB5124008, and KB5122878. These issues are not isolated to home users; enterprise environments are also affected, with Windows 10 Enterprise LTSC 2016/2019 and Windows 11 23H2 and later being impacted.
It’s worth noting that this is the latest in a series of problems linked to Microsoft’s September updates. Just last week, the company released out-of-band updates to fix issues affecting Remote Desktop Services failures, Hyper-V, and USB audio problems triggered by these security patches. However, it appears that not all audio-related issues have been resolved yet.
For now, affected users can try a temporary workaround, but a permanent solution is still pending. In the meantime, it’s essential for users to be aware of this issue and take steps to mitigate its impact. If you’re relying on File History to back up your files, consider verifying that your backups are complete and accessible before installing any further updates.
Ultimately, these issues highlight the importance of thorough testing and validation processes in software development. As we move forward with increasingly complex technologies, it’s essential for companies like Microsoft to prioritize quality assurance and user experience. In the meantime, users should exercise caution when applying security patches and keep a close eye on system performance to ensure that their critical functions remain intact.
Source: Bleeping Computer — 2026-09-21