White border around windows and white background

Hi, from some weeks I'm having a problema with Windows in coherence mode.
A white border around the windows appears and in some windows all the background changes to white.
I'm attached some screenshots.




My system is a Mac Mini M4 Pro with 64GB RAM Sequoia 15.6 and the installed version of Windows is Windows 11 24H2 26100.4770
Regards

 

I am having this same issue.

 

Same issue since a few weeks on my MacBookPro M4 w 48GB. It seems shadows and blurring background isn't running correctly (i guess it is since Parallels Desktop v26)

 

Same issue on MacPro Intel running latest Windows 11 24H2 26100.6725
Version 20.4.1 (55996)

In addition, windows under coherence keep going out of focus (being pushed behind other apps / windows on macOS) when selected ie. start menu, file manager etc.

 

@Adarsh Jeetun
Hi there! It's been over two months already -- is there any update or fix for this issue? It's been quite a long time.

 

Hi, this is happening since summer in 24H2. an update fixed the issue on my side, 2025-08 Cumulative Update Preview for .NET Framework 3.5 and 4.8.1 for Windows 11, version 25H2 for arm64 (KB5064402). but it came back with 25H2 yesterday's latest Prod patches, so the issue is back

2025-10 Cumulative Update for Windows 11, version 25H2 for arm64-based Systems (KB5066835) (26200.6899)
2025-10 Cumulative Update for .NET Framework 3.5 and 4.8.1 for Windows 11, version 25H2 for arm64 (KB5066128)

Everything was fine until this moment
2025-09 Cumulative Update Preview for Windows 11, version 25H2 for arm64-based Systems (KB5065789) (26200.6725)

so uninstalling both latest October patches fix the issue

 

I having the same issue, Can someone guide me please?

 

There is no workaround yet, only Parallels and Microsoft Teams can fix it. Frustrating that no news are shared on the progress, and the newest 26.1.2 is not fixing this neither

 

With Parallels version 26.2.0 (57363) my Windows 11 is working properly again. No more white borders around Start menu and no background when a system (admin) dialog appears.

Thank you Parallels <3

 

Sorry, I have to revoke my previous comment. After a restart of my macbook the white borders are back. It seems the issue is still not fixed completely.

 

I have an update.

My Win11 installation is a little bit older and was still in "Insider Builds". Somewhere mentioned the white border issue happens related to the insider builds. I never figured out how to exit the insider preview build stream.

At the weekend I found a way to fix my Win11 installation. With this solution I could also change the setup country from US to Germany, where I am.
https://www.reddit.com/r/WindowsHelp/comments/1mbiys6/how_to_change_setup_device_region/
But be careful it is tricky. It means you are resetting the installation to a "new device" state. You need to add (at least temporarily) a new user. But as soon as you're finished, you can login back to your previous account. All programs are still installed.

These are the steps to refresh the installation:

1. Run C:\Windows\system32\sysprep\sysprep.exe
2. Hit OK
3. Your PC will be rebooted and you'll see a part of the setup process again.
4. Select your desired region.
5. Click through the rest.
6. Create a new user.
7. Hooray, the setting has changed. Your PC is not formatted.
8. Go to start (Windows button) > power > instead of restart or shut down, click logout, this will take you to the welcome screen with 2 accounts to choose.
9. Sign back in with your old user account.

​

As you can see, white borders are gone. Under some circumstances the white border will still be shown, but this is not the default behavior anymore.