Windows 10 V1809: Write bug in ZIP feature

[German]Another (nasty) bug has become known in Windows 10 October 2018 Update (Version 1809). The internal ZIP function is more or less unusable, because it does not work reliably during unpacking. If a file is already available at the destination when unpacking a ZIP archive, Windows 10 does not copy the archive file. Addendum: Microsoft has confirmed the bug, they know it, fixed it in Insider Preview of Windows 10 19H1, but probably lets the users of Windows 10 V1809 wait until November 2018.


Windows 10 supports an integrated ZIP function, which is accessible via the context menu in Explorer. You don't need any external program to quickly create a zip archive with files, or to unzip a zip archive file. This features has been available since decades in Windows.

But there is a bug in Windows 10 V1809 Zip feature

I came on Saturday across this post at, where the issues with the Zip function under Windows 10 V1809 is addressed. Woody Leonhard noticed user messages in his own forum and on complaining about issues with the zip function. Here is the text, a user wrote on

Ever since the October update, the overwrite confirmation is missing from zip files.

I noticed that whenever I move something out of a zip, the "do you want to replace these files" dialogue never shows up, it just does it.

I've reinstalled windows and it still does it, it's only on the october update. Pretty nasty bug since you can accidentally overwrite a file and have no way of getting it back.

If a user tries in Windows 10 V1809 to extract a file from a zip archive into a target folder and this file already exists, there is no warning against overwriting the target file. In the thread there is a reference to this 2nd article, which reports the following: Windows 10 1809 File copy problem – anyone else experience this

When dragging newer files (with same name as in the destination folder) from a compressed folder to a regular folder it looks like the file copy happens, you can see the transfer progress, but when you check after no files have been updated. Anybody else have this?

Martin Brinkmann has shown the dialog in question here, which should actually appear and ask if it should be overwritten. I tested it on the fly and unpacked a ZIP archive. The second time I unpacked the ZIP archive into the same destination folder, it looked as if it files was being copied. But the target file is simply not overwritten when copying again.

Also the attempt to extract individual files from the ZIP archive into the target folder by Drag&Drop to overwrite a modified target file there does not continue. Windows shows a copy progress bar, but the target files remains untouched.


Addendum: The bug was reported in Insider Program

Seaching the weg during writing this post, I didn't found other hits, where the issue has been mentioned (well, it was midnight during writing, maybe I was a bit tired). This morning a German blog reader mentioned, that the bug has been reported months ago – see the Tweet below.

I don't know your opinion. But for me it's a clear indication, that Microsoft's Windows as a service is failing. The ZIP feature has been in use since decades, and then a simple 'feature update' kills such a feature – unbelievable.

Addendum: Microsoft confirms that bug, no fix

Microsoft has confirmed that ZIP bug within the MS Answers forum post If you copy files from a .ZIP file without extracting them, they might not be copied or moved correctly, even though it looks like they have been. My German MVP collegue Martin Geuß mentioned within his German article ZIP-Bug im Windows 10 Oktober Update wird immer peinlicher, that Microsoft was aware of this bug. They fixes it within Insider Build for Windows 10 19H1 branch. But users of Windows 10 V1809 have to wait until November 2018 for a patch. Let's hope, the rollout of Windows 10 V1809 will be on hold until that November patchday.

Cookies helps to fund this blog: Cookie settings

This entry was posted in issue, Windows and tagged , . Bookmark the permalink.

One Response to Windows 10 V1809: Write bug in ZIP feature

  1. Pingback: Microsoft admits to Zip file wiping bug and fixes it — but not for Win10 1809 customers @ AskWoody

Leave a Reply

Your email address will not be published. Required fields are marked *