Microsoft admits it broke a Windows 11 backup feature — but it's now fixed

A bug in Windows 11's September update broke File History Microsoft admitted the backup feature was scuppered and has apparently now fixed it However, the cure is in an optional update, so it might be best to wait for the full release of the upgrade next month Microsoft has admitted that Windows 11 has a bug that messes up a backup feature in the OS, although a new optional update fixes it (but not quite fully).

Windows Latest reports what's been a slightly odd tale in that the bug in File History has been kicking about since the September update first emerged over two weeks ago, but Microsoft didn't acknowledge it — even though it was a widely reported issue.

File History is a feature that enables you to keep files backed up to an external drive, and while it doesn't see a whole lot of use these days, it's obviously important for those who do still avail themselves of the functionality.

Microsoft informed Windows Latest that: "After installing the September 2026 Windows security update KB5124008, some customers using File History, might be unable to create or update backups.

File History is used to back up files to an external drive or network location." The good news here is that the latest September update, which is optional — it's a preview of the October update in fact — does fix this bug, as confirmed by Windows Latest, but it seemingly doesn't fully iron out every issue with File History.

Windows Latest noticed a post on Microsoft's Learn portal from a user who confirms that the new September preview update does mean that File History is working again and making backups, but there still appears to be an issue with the 'Run now' ability and problems with synchronization of save times therein.

However, this isn't a bug caused by Microsoft's recent work on Windows 11, and in fact this glitch dates back to a Windows 11 update in July 2026.

Analysis: update skeptics (Image credit: Mark Pickavance) At least File History appears to be cured of this latest feature-breaking bug, and hopefully the other problem highlighted on Reddit will be fixed before too long.

You don't necessarily want to download an optional update, of course, as it may bring in other bugs — after all, it's still a beta.

The safest bet is to wait for the October update to arrive in two and a half weeks (on October 13) and then install that as the remedy for your File History blues (while temporarily keeping backups a different way , manually or on OneDrive, in the meantime).

Windows 11 bugs have remained a problem throughout 2026, and every year before for that matter (particularly with the 24H2 release).

Microsoft still needs to do better in this regard considering this is one of the thornier issues that has continually dogged its OS, which it's busy fixing this year .