Maplespe
CustomBlur (IComposition) is broken on build 26x00.7019 (KB5067036) and later
Describe the bug:
After updating to build 26100/26200.7019 (KB5067036 aka the 2025-10 Preview CU for Windows 11 24H2/25H2), the default CustomBlur method no longer works properly, instead only showing clear transparency (no blur, no aero, just the color).
Title bars & window frames affected by the Override DWMAPI effect does not exhibit this issue.
To Reproduce: Just install update KB5067036.
Screenshots & Demo:
https://github.com/user-attachments/assets/76dadc46-36a8-474f-b495-4f2ab8504925
Additional information:
- OS Version Tested : 26200.7019
- Software Version : 2.3.1
What other third-party software do you use: None
Additional context: From other related reports, it seems whatever change that caused this and similar bugs was introduced a few updates before this one, so the affected builds could range from 26x00.6972 to 26x00.7019+. ~~I did try to test on the current stable builds, 26x00.6899 and 26x00.6905, but unfortunately I could not download symbols for these builds (yet), so the last known good 24H2/25H2 build for now is 26x00.6725.~~ Update: Managed to get symbols for 26x00.6899 through 26x00.6905 using this tool, so the known good build is now those.
Other reports with this same issue: #597, #595, #608, #609
see my comment https://github.com/Maplespe/DWMBlurGlass/issues/595#issuecomment-3470506432
Because of that windows update, my transparency does work but if the screen isn't focused (clicked in) it gives a white transparent screen
Same issue, I'm on Windows 11 25H2, some apps like old windows image viewer, winaero and other apps have just transparent effect instead of mica which I've selected, whereas some modern windows app like new snipping tool, paint,etc have the mica effect, I just installed this app yesterday, and running latest version of it as of 9 November 2025.
I also use your Explorer Mica effect app and Windhawk, if it helps
Hey guys, I wanna point out that I fixed mine simply by adjusting the opacity back to 0%, it has always been at 0% but for some reason with the windows update it set it to 50% opacity or so, maybe try readjusting the settings again just to make sure
Hey guys, I wanna point out that I fixed mine simply by adjusting the opacity back to 0%. It has always been at 0%, but for some reason with the Windows update it set it to 50% opacity or so. Maybe try readjusting the settings again just to make sure.
It helps a little, but this is clearly not the perfect solution. I think the tool might need an update
Same issue here, it seems that windows update broke it. Aso, saving the config was also broken with the same windows update. If you change a setting, press the save icon, and restart the application, your settings do not persist anymore. At least on my env.
The only temporary solution is to use Mica For Everyone, and in the "Global" rule, change the Background type to "Acrylic". At least in my case, I'm still using DWMBlurGlass to configure the title bar color, blur level and set the title bar buttons to small, like in Windows 7.
Mica for everyone config
mica foreveryone i cannot get it to work on firefox... toolkit.legacyUserProfileCustomizations.stylesheets
This is still happening on the 2.3.2 beta. I'm running 26100.7171, but I believe the 26100 vs 26200 part does not matter as it's the same on both.
@diarrhea3 It does actually, I had the same issue as you but updating to 26200 fixed it, the fixes in the latest beta of DWMBlurGlass specifically target 25H2.
Can confirm that 2.3.2 Beta 1 has fixed this bug. Thanks everyone for the feedbacks and @Maplespe for working on the fix. I have updated the issue name + description and will now close it.
@Skyyblaze That’s good to know thanks. Well I’m using LTSC 2024 which can’t be updated beyond 26100 so I guess I’m stuck with it, unless the developer fixes it for 24H2 as well.
@diarrhea3 I see that's unfortunate, maybe the final release of the 2.3.2 will work eventually.