virtualbox.org

Saved the state of Ubuntu 18.04.5 (64-bit) guest OS. When trying to restore, Urgent Guru Mediation dialog appears after 20+ sec or so. (Repeatable - happened twice the same)
Platform: Lenovo Thinkpad T15 i7-10610U Windows 10 Ent (64-bit) v1909 18363.1443 - Hyper-V is off.
Guest VM still works if I power off and power on, just cannot save and restore state.

Example errors from VBox.log (attached):

00:00:26.781711 ERROR [COM]: aRC=VBOX_E_VM_ERROR (0x80bb0003) aIID={4680b2de-8690-11e9-b83d-5719e53cf1de} aComponent={DisplayWrap} aText={Could not take a screenshot (VERR_NOT_SUPPORTED)}, preserve=false aResultDetail=-37

<repeats a few times>
ends with

00:00:31.677073 emR3Debug: rc=VERR_IEM_INSTR_NOT_IMPLEMENTED

[/size]
Win10 cmd:[/color]

PS C:\windows\system32> DISM /Online /Get-Features

Deployment Image Servicing and Management tool
Version: 10.0.18362.1379

Image Version: 10.0.18363.1443

Features listing for package : Microsoft-Windows-Foundation-Package~31bf3856ad364e35~amd64~~10.0.18362.1440
...
Feature Name : HypervisorPlatform
State : Disabled
...
Feature Name : Microsoft-Hyper-V-All
State : Disabled

Feature Name : Microsoft-Hyper-V
State : Disabled

Feature Name : Microsoft-Hyper-V-Tools-All
State : Disabled

Feature Name : Microsoft-Hyper-V-Management-PowerShell
State : Disabled

Feature Name : Microsoft-Hyper-V-Hypervisor
State : Disabled

Feature Name : Microsoft-Hyper-V-Services
State : Disabled

Feature Name : Microsoft-Hyper-V-Management-Clients
State : Disabled
...

iSteveK wrote:Hyper-V is off

No, it's not.

Please read HMR3Init: Attempting fall back to NEM (Hyper-V is active), and especially pay attention to the bcdedit command.

You are correct that Hyper-V is still enabled.

However, I did read the link previously and run the bcdedit command in an Admin cmd window and it reported The operation completed successfully (and then I rebooted - I did that again just now and still no joy). So something else is turning on Hyper-V. This is a company laptop, so IT may be controlling this and I have no choice but to live with it.

You can easily check the status of that by doing a bcdedit /enum. The {current} entry shows the status of the loaded config. If hypervisorlaunchtype is absent or set to Off, the hypervisor will not load. It it is set to Auto, it will load. And if it is loaded, the VirtualBox guest will have Attempting to fall back to NEM line in the log. In my PC it is absent.

There are lots of things, both in the OS itself and third party apps, which can activate the hypervisor apart from Hyper-V. If the hypervisor is not loaded, you will not see that line.

iSteveK wrote:and then I rebooted

How?

the NEM tutorial wrote:5. Enter this command:

shutdown -s -t 2

6. When the computer turns off, unplug it for 20 seconds.

Note, no reboot.

iSteveK wrote:This is a company laptop, so IT may be controlling this

This is a distinct possibility, if following the above instructions does not help. Do you need Virtualbox for work? Ask your boss to help you convince IT to ease up on the restrictions. If you don't need Virtualbox for work, will they like you installing Virtualbox on their computer, pink-slip-wise?