All Virtual machines stopped working

[Elun]

Hello.
Today all my virtual machines stopped to work for some reason. I tried to update virtual box version, tried to downgrade, nothing helps.
Specs:
VirtualBox had version 4.3.26 when i got this issue. After that i tried 4.3.10, 4.3.12, 4.3.14, 4.3.28.
Amount of host RAM: 32Gb.
Amount of RAM for guests: from 2 to 12 Gb. Logs in attachment for VM with 2Gb.
Host: Windows 7 x64 SP1.
Guest: different(win 7 x32/x64, windows xp x32), logs attached for Windows XP x32.
What is interesting: Ubuntu guest works without any problem.

UPD: looks like only 32bit system is not working anymore for some reason. 64bit systems is ok

[mpack]

Please don't provide VBoxStartup logs unless we ask for them. If the VM starts up (not the same as the guest OS starting) then the VM startup log is irrelevant, as in your case.

00:00:04.273283 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
00:00:04.273283 !!
00:00:04.273284 !! Guru Meditation -4014 (VERR_VMX_INVALID_GUEST_STATE)
00:00:04.273297 !!
00:00:04.273316 !!
00:00:04.273316 !! {mappings, <NULL>}
00:00:04.273316 !!

I seem to recall that this error indicates that another VM platform is running, or has been running and didn't clean up after itself very well. It may also be caused by some antivirus apps.

This would affect any guest that uses VT-x.

[michaln]

Guru Meditation -4014 (VERR_VMX_INVALID_GUEST_STATE)
...
I seem to recall that this error indicates that another VM platform is running, or has been running and didn't clean up after itself very well. It may also be caused by some antivirus apps.

Not at all. VERR_VMX_INVALID_GUEST_STATE actually indicates a bug in VirtualBox.

That said, it doesn't make sense that it would spontaneously started happening for previously working guests. Something must have changed, and if it wasn't VirtualBox, what was it?

[Elun]

Looks like i found root of problems. I'm beta tester of Dr.Web and looks like there is smth wrong in new update and it is not VBox issue.

[mpack]

Does it use VT-x? It's something that a few AV apps are starting to do. I regard it as a worrying trend, if my company was ever to insist that I install that kind of AV on my work PC.