File Explorer window closes when I right-click and open BRU

[Growltiger]

This just started recently.
I right-click a folder, then Show more options, then Bulk rename here, and the File Explorer widow vanishes.
BRU works perfectly, then I have to open Explorer again. Annoying when I have several tabs open.
I am up to date with Windows 11.
Any suggestions please?

[Growltiger]

Some more tests show that whether Explorer crashes depends on which folder I right-click on. Most make it crash. It may be ok with folders that don't have any files in them, only other folders. But I'm not sure.
The failure is in shcore.dll:
Fault bucket 1979146705596513808, type 4
Event Name: APPCRASH
Response: Not available
Cab Id: 0

Problem signature:
P1: Explorer.EXE
P2: 10.0.26100.9278
P3: 4de7f396
P4: shcore.dll
P5: 10.0.26100.9278
P6: 01dbc34f
P7: c0000005
P8: 0000000000038a5a
P9:
P10:

[Admin]

The biggest clue is the Windows build:
26100.9278 = Windows 11 24H2 with KB5120998, an optional preview update released 27 August 2026. The first report was 30 August. Microsoft says the update includes File Explorer changes and, at present, lists no known issues for the update.

The c0000005 exception is an access violation. shcore.dll is a Windows shell DLL, but seeing it as the faulting module doesn't prove Windows itself is solely responsible: an Explorer shell extension can corrupt or pass bad state and the eventual fault can occur inside shcore.dll.

BRU's "Bulk Rename Here" is indeed implemented as an Explorer shell extension/context-menu handler (BRUMenuHandler), so it runs code in the Explorer context.

BRU itself then continuing to work perfectly is quite consistent with the shell-extension portion causing Explorer to die while starting BRU.

I'd test these in this order:

Check Update History for KB5120998. If it was installed just before the problem began, temporarily uninstall KB5120998, restart, and try exactly the same troublesome folder again. Microsoft documents the path as Settings > Windows Update > Update history > Uninstall updates.
Because KB5120998 is explicitly a preview/non-security update, this is a particularly useful A/B test.

Check the BRU version. The current release is 4.1.0.1. If an older version is installed, upgrade before doing much more troubleshooting.

If removing KB5120998 doesn't change anything, disable the BRU Explorer extension temporarily. BRU's installer allows installation without “Install Windows Explorer Extension.” An official-forum recommendation for removing the context-menu item is to reinstall with that option deselected.

If Explorer immediately becomes reliable, you've isolated it to BRU's shell handler or an interaction involving it.
Also test other Explorer-modifying software. ExplorerPatcher is especially worth checking if installed: a previous BRU crash report was traced by BRU's administrator to ExplorerPatcher.amd64.dll, and removing/reinstalling ExplorerPatcher fixed that user's problem.
Microsoft's Autoruns can also enumerate Explorer shell extensions, making it useful for temporarily disabling third-party handlers one at a time.

I would not spend much time yet investigating why folders containing files seem more likely to trigger it. That's useful reproduction information, but the striking Aug 27 -> Aug 30 timing makes KB5120998 the first thing I'd eliminate.

If uninstalling KB5120998 makes the crash disappear, that would be a very strong result to post back to the BRU thread: “Rolling back from 26100.9278/KB5120998 fixes it.” If it still crashes on the previous Windows build, I'd next focus on BRUHere64.dll/BRUMenuHandler and other Explorer extensions.

[Growltiger]

Thanks.
I have uninstalled KB5120998, the preview.
(I never normally install a preview, but I did it this time in the hope of getting rid of a Microsoft bug where it keeps telling me I need to turn Windows Defender on. Of course it is on and working normally. Many people have reported this, they have admitted the bug and I now see a fix is promised for the September update.)

I'm sorry to report the problem with the BRU right-click is still there, exactly the same.
Faulting application name: Explorer.EXE, version: 10.0.26100.9168, time stamp: 0x77cb28fb
Faulting module name: shcore.dll, version: 10.0.26100.9168, time stamp: 0x2c58c6a0
Exception code: 0xc0000005
Fault offset: 0x000000000003a4da
Faulting process id: 0x3080
Faulting application start time: 0x1DD3922F4276531
Faulting application path: C:\WINDOWS\Explorer.EXE
Faulting module path: C:\WINDOWS\System32\shcore.dll
Report Id: d1a0f69c-6148-4e8c-b9ee-1c6f24f4d883
Faulting package full name:
Faulting package-relative application ID:

Please let me know if I can do any more to help pin this down.

[Growltiger]

I should have mentioned that I'm running the latest BRU.
I have never used ExplorerPatcher.
Explorer is completely reliable apart from with BRU, I have tried some other right-click programs listed and it isn't crashing.
I have no doubt the problem lies with Microsoft, but it would still be nice to make it work.

[Growltiger]

I should have also mentioned that when before I first posted about this I had done a:
sfc /scannow
and a
DISM /Online /Cleanup-image /Restorehealth
and neither reported any errors.

I just uninstalled BRU, restarted, then installed it again. It is now working perfectly.
Perhaps it will now be OK.