Warning! - Windows Update this month(Apr 15 2025) broke Windows HostOS running VBox

No solution yet.

If you are running VBox on Windows, <do not install this month’s “Patch Tuesday” udpates until it’s determined which one broke VBox.and/or VBox pushes a fix. The essential error is that VBox is unable to access he Windows kernel throwing an ntdll error.
Here is the thread
https://forums.virtualbox.org/viewtopic.php?f=6&t=67355

Unfortunately for me, I’ve been creating my VBox disks using the native vdi format. Been careless about that, in general unless there is a better reason to do so, I create disks in the raw format which has the greatest flexibility moving between virtualization technologies.

But, if it’s important enough to anyone bitten by this bug, probably the only current solution is to roll back the Windows updates.

TSU

Just some food for thought…
Although this issue isn’t important to anyone running Virtualbox on openSUSE or any other non-Windows, this is a pretty significant issue for a very large number of people who might have relied on using VBox for Production use. For a couple days, they would have been faced with significant down time and even today (3 days after the Win Update) a proper fix still doesn’t exist. Although I can’t find VBox use statistics, some reasonable guesses based on older published stats is that 70% of VBox Users are on Windows, whatever the overall download number might be.

Considering this problem almost certainly affects a <very> significant number of Users with the highest severity level, you’d think that VBox likely should be marshaling max resources to solve this emergency issue. There have been plenty of speculation how many people Oracle might have working on VBox after its acquisition with speculation from “Only four” to “More than four.” Regardless what the number might be, though this problem probably affects relatively few members of this Forum it might serve as a measuring stick what to expect if you are hit with an emergency and VBox might be critically important to you.

It also seems that there is no clear way for anyone to contribute to solving this problem. Although VBox source is now open source, all the included compiling tools and libraries appear to be for *NIX, it seems that compiling for Windows is done “somewhere else” so there is no clue whether the existing problem might be solved using a different compiler or if the existing compilation can be modified. It may be that Windows compilation isn’t even done by Oracle or core members of the development team.

TSU

For those following this issue,
Although I haven’t seen any big announcement anywhere it appears that…

  • One of this month’s Windows updates seems to have silently addressed the VBox problem, the ntdll error no longer is thrown.
  • VBox has released a new version 4.3.18r100309.

I’d recommend installing both.
BTW - The openSUSE Guest popped up a notification that VBox Guest additions aren’t consistent with the new VBox version, so as always I recommend updating those to remain consistent. Before upgrading, I noticed some Guest additions features continued to work (eg cursor seamlessly working from VBox display to HostOS display without a lock) but I wouldn’t expect everything to work.

TSU