KB5055523 breaks Explorer patcher - Taskbar style Windows 10 (explorer patcher).

[Spc0]

Today i installed updates on my Win 11 24H2.

KB5055523 breaks explorer, it does not open.

When i click explorer icon or click on my username folder on desktop it does nothing.
I also can't start explorer if I type into run: explorer.exe

Main window of explorer does not start up, nothing happens.

If i uninstall KB5055523 everything works perfectly fine.

Fixes in April release for 24H2:
https://www.bleepingcomputer.com/news/microsoft/microsoft-april-2025-patch-tuesday-fixes-exploited-zero-day-134-flaws/

We need to check what Microsoft did that disabled EP.

Thanks.

[pyrates999]

Check what happens when using the console in explorer patcher. Open up the properties application for explorer patcher, go to advanced, and click on enable console. Copy and paste the results here.

[pyrates999]

also check if you enabled the option register as shell extension, disable it by opening up the EP properties application, go to File Explorer, and untick Register as shell extension.

Here's why: https://github.com/valinet/ExplorerPatcher/wiki/Using-ExplorerPatcher-as-shell-extension

[pyrates999]

and check for explorer.exe dumps in %LOCALAPPDATA%\CrashDumps

then rename the file extension to .txt and upload it to here

[Spc0]

I have more details regarding explorer.exe

So i uninstalled Explorer Patcher before installing KB5055523 so that KB5055523 would update windows without Explorer Patcher even present in the system.

But it still breaks explorer.exe from opening up window.
So even if I try to use original taskbar without EP after this update explorer.exe doesn't open any windows, it is really hard to navigate as you can't browse any disks or run any applications, you can only use command prompt by typing cmd into run.

So i don't think it's EP's fault.

I also tryed to install fresh install of windows into virtual machine and before any driver updates or anything i downloaded all windows updates including KB5055523, after windows updates installation if i run EP, explorer.exe works.

I also tryed this trick on a physical machine and if i install KB5055523 before anything else, it works, explorer.exe opens a window to "home" or "This PC" depends what you set it to in settings.

However on existing installation of windows 11, on 3 physical machines if i install update KB5055523 explorer.exe doesn't open when clicking on folder, explorer.exe icon or running it via run, even if ep is not even present.

This seems more likely Microsoft bug that i have no solution to fix.

Also Windows logo key + E doesn't open explorer.exe however taskbar loads at windows start.
Even in safe mode with no drivers or additional services loaded explorer.exe doesn't open any windows nor does Windows logo key+E

Only fix is by uninstalling KB5055523.
Same behaviour on all 3 physical machines that i installed KB5055523, on others i put it on hold for now.

[Spc0]

I found what's causing it.

I had applied some tweak in winaero tweaker that breaks explorer.exe.
After clicking restore all tweaks to default explorer.exe now works.

So it's not explorer patcher issue.

Anyone that has similar problem, here's your answer and solution to the problem, if you used any registry tweaks or winaero tweaker, just click restore all tweaks to defaults.

Thank you everyone.

This tweak breaks explorer.exe:

https://winaero.com/get-colored-title-bars-in-windows-10/

Before PATCH KB5055523 it worked normally for years even for Windows 11.

[Spc0]

Looks like a BUG with windows themes is the issue.
If i set everything to defaults, clear all entries in registry from all tweaks that i use and apply .theme file, .deskthemepack

Explorer breaks.

This means this issue is related to theme packs and theme that is being applied.

To reproduce this issue:
Install KB5055523 to any Windows 11 24H2, home, professional, enterprise, server etc etc.

After reset+installation apply theme:
test-theme.zip

Explorer.exe doesn't work anymore.

To restore function of explorer.exe go to "personalize" with right clik on desktop, and select windows default theme.
explorer.exe now works.

I had to replace whole C:\Windows\resources directory in order to get themes working back again.
I replaced it with original microsoft files from different computer after KB5055523 update.

Now the issue is completely gone.
I can apply any theme.

[pyrates999]

thank you for finding out what it is