I have had this present issue with Windows 11 since 24h2, which sadly has not been resolved and still continues in 25h2.

I use teracopy for moving and copying files, which worked fine on 23h2. But since 24h2, if I open teracopy, the whole os crashes. it not matter when i transfer a file or anything. Just open teracopy and instantly Windows 11 crashes. If i start windows in normal bare metal mode, i do not have any issue. So i know it's related to Windows 11 and unraid not handling something that has changed since 24h2 correctly. I have zero clue what causes this bug or when the issue is going to be fixed. I am unsure if there is something in windows that needs to be changed or updated. I have got a dump stack that i hope the devs can look through and hopefully update unraid to prevent such an issue.

DumpStack.log

Hi

I also use teracopy & have just done a new Windows 11 VM install in the last week or so - 25H2 OS Build 26200.6584 teracopy v3.17 Intel 14th gen CPU - Unraid 7.1.4

everything is working ok no crashes & have moved about 1TB so far

So it should work ok

VM details are CPU host passthrough - machine i440fx-9.2 - vdisk is VirtIO - graphics Virtual - video driver QXL (best - network model virtio-net

I used a windows ISO downloaded from Microsoft but ran it through the Chris Titus winutil to get what he calls a microwin version but it just strips junk out etc local account install etc It makes for a really quick clean install. but if anything this may cause an issue not fix it in this problem.

I also always pin my CPU cores in the VM config & never use CPU/Core 0/1

any further information you need just ask but at least you know it should work if that helps !?!

Edited November 17, 2025Nov 17 by ThumperZ

14 hours ago, ThumperZ said:

So it should work ok

Ok this is interesting as i had created a new vm from scratch and it works fine. If i enable windows sandbox or nested virtualisation, then the open teracopy, the VM crashes. I have found out the issue is due to enabling virtual machine platform in features. Tuned it off and teracopy works fine.

It turns out that windows sandbox is basically a vm and as i have Windows 11 vm running, then enabling sandbox, creates basically a vm inside a vm ie nested virtualisation and teracopy does not like that. It's similar here https://forums.unraid.net/topic/138451-hyperv-nested-virtualization-on-amd-threadripper-pro/ I do wonder if it's kernel thing that needs to be fixed and updated in, however, many months time. In which case I can wait it out.

yea sounds like the VM in a VM is the real issue.. I totally forgot sandbox even existed.