Enhanced Metafile (EMF) Rendering regression during Windows 10 April 2021 Update

Andrew Brock 21 Reputation points

We have an EMF file that consists of some black lines/dots and coloured lines.

In build 10.0.18363.1440 this views fine in MS Paint.

In build 10.0.18363.1500 this file has no coloured lines or any element that isn't coloured black.

I can't help but think that there's some kind of regression between these two builds that has caused a regression in this rendering behaviour (i.e the April 2021 update broke something).

I've uploaded the EMF file to https://sahmri.blob.core.windows.net/ict/microsoft-support/lines_and_dots.emf

...so you can try for yourself.

Windows API - Win32
Windows API - Win32
A core set of Windows application programming interfaces (APIs) for desktop and server applications. Previously known as Win32 API.
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Accepted answer
  1. Marlon Marin 81 Reputation points

    I built a new VM using Windows 10 March Update ISO and opened an EMF file without issues.


    I downloaded the April update and installed manually.
    I confirmed as stated the EMF opened but the color lines were missing.




    I downloaded and installed the June update KB5003690, and the issue was resolved.


    Updating the systems with the latest monthly updated should take care of the problem.

    1 person found this answer helpful.

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  1. Song Zhu - MSFT 906 Reputation points

    I think this update caused the emf file to display abnormally.

    You can try to continue to update the subsequent repair patches to solve the problem.

    If the answer is helpful, please click "Accept Answer" and upvote it.

    Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

    1 person found this answer helpful.

  2. Andrew Brock 21 Reputation points

    It's not listed via wmic and uninstall via wusa fails as it does exist - except it does appear in the Windows Update history - as you can see from the below screenshot.


  3. Ramon Teixidó 1 Reputation point

    Same problem here. We've thousand of emf files where suddenly dissapeared some coloured lines.
    If you edit the file (i.e. with adobe illustrator) select the lines, "outline the path" and save it as an EMF again it is shown in the right way, but obviously it's not a useful solution if you have thousands of files to check, and you don't know which lines are showing in a wrong way.

    EMF files suddenly became useless, if Microsoft doesn't solve it this will be the end of this file format.

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