Repair VB to get the created virtual machines working again

[ALFIL]

Hello,

Yesterday the virtual machines I had created and working fine suddenly stopped opening.

I have uninstalled and reinstalled the latest version and the created machines still appear but I could not open any of them either.

I tried to create a new one but it was not possible to do so.

It is obvious that VB is broken and I would like to be able to repair it and make the created virtual machines operative again.

I would like some advice on how to repair it. Thank you very much for your help

[mpack]

Pick a VM, run it to completion, and then provide us with a zipped VM log file.

Make sure the VM is fully shut down, then right click it in the manager UI. Select "Show Log" and save "VBox.log" (no other file) to a zip file. Attach the zip here.

[ALFIL]

Hello mpack
I attach the requested VBox.log.
Regards

[mpack]

00:00:00.661553 HM: HMR3Init: Attempting fall back to NEM: AMD-V is not available
00:00:00.712158 NEM: info: Found optional import WinHvPlatform.dll!WHvQueryGpaRangeDirtyBitmap.
00:00:00.712171 NEM: info: Found optional import vid.dll!VidGetHvPartitionId.
00:00:00.712175 NEM: info: Found optional import vid.dll!VidGetPartitionProperty.
00:00:00.712224 NEM: WHvCapabilityCodeHypervisorPresent is TRUE, so this might work...

Disable Hyper-v on the host.

Increase CPU cores to 2.

Enable 3D acceleration.

Discard the saved states: these are not guaranteed to be compatible across VirtualBox versions. The whole idea of a saved state is that there's no need to go through the full boot process if nothing has changed. Something changed.

[ALFIL]

Hyper-V was always disabled and continuing with what you tell me, the next thing I did was to discard the saved machines to shut them down..

On Startup now the shutdown machines opened normally! The problem has been solved.

Thank you very much!

[mpack]

Hyper-V was always disabled

Why do people insist on arguing with the log? Hyper-v is enabled. I showed you the relevant portion of the log, that should have been more than enough for you.

[scottgus1]

ALFIL, if you look through our Hyper-V tutorial HMR3Init: Attempting fall back to NEM (Hyper-V is active) you'll see why you needed to

Disable Hyper-v on the host.

even though

Hyper-V was always disabled

See the part about the Windows Features box.

[ALFIL]

I said that Hyper-V was disabled because I had checked it when the problem started and before asking here and I do not understand how the log shows that it was enabled.

There must be another signal that the log receives and interprets it as Hyper-V enabled when it is not.

When I say it was not enabled, I mean that the box that says Hyper-V in Windows features was unchecked.

I did not say it to say something and do not get a bad impression from me. I know it was deactivated because I had verified it as I said at the beginning. Something must have happened for the log to have indicated it as activated.

Besides, I did not modify it and VB works.

Regards

[scottgus1]

When I say it was not enabled, I mean that the box that says Hyper-V in Windows features was unchecked.

Did you see my post above yours?

[ALFIL]

Hi scottgus1,

Yes, I saw that and that was what I had done.

I said that because there might be somewhere else where Hyper-V could be enabled and I was unaware of it.

Regards

[scottgus1]

OK, good. The point about Windows Features in the tutorial is that Windows Features does not show all the things that could be using the underlying Hyper-V engine that the VM vbox.log reports on.

So merely looking at Windows Features and seeing that the "Hyper-V" checkbox is unchecked is quite insufficient.

When the log contains the lines Mpack posted, it means the underlying Hyper-V engine is running, even if the Windows Features Hyper-V box is unchecked. It is the underlying Hyper-V engine that interferes with optimal Virtualbox operation.

You may find that your VMs are running OK enough now, but they will run better if you can fully disable the underlying Hyper-V engine. If you still see the green turtle in the Status bar of the VM window, Hyper-V is still on.

However, now that you got past the saved state issue, if your VMs are good enough, then running with the green turtle is not a problem. Turning off Hyper-V completely does involve undoing some of Microsofts newer security features, so there is a risk assessment: Run high security and slow Virtualbox, or average but good enough security and high Virtualbox.

[ALFIL]

Thank you for the information. I was unaware of it.

I opt for medium security and VirtualBox high, how should I proceed?

[scottgus1]

If you still see the green turtle in the VM window's status bar, follow the tutorial to disable Hyper-V on the host. If you have a blue V symbol, then Hyper-V is off. See the tutorial for these symbols.

[ALFIL]

Ok, Thank you very much!