virtualbox.org

Just updated to Version 6.1.28 r147628 (Qt5.6.2). First thing after updating and rebooting I attempted to start my Linux Mint VM and I got the error; Virtual Box error ? Failed to open a session for the Virtual Machine Linux Mint. The details shown in the error were:

Failed to open a session for the virtual machine Linux Mint.
Call to NEMR0InitVMPart2 failed: VERR_NEM_INIT_FAILED (VERR_NEM_VM_CREATE_FAILED).
Result Code: E_FAIL (0x80004005)
Component: ConsoleWrap
Interface: IConsole {872da645-4a9b-1727-bee2-5585105b9eed}

I then attempted to open another VM Zorin OS16 Pro - same error.

Until this can be remedied, I'd like to find out if there is a method whereby I can rollback this latest update?

Host:
Windows [Version 10.0.19043.1288] updated to 10/22/2021 1800Z
CPU: Intel Core i5 9600K
MoBo: Gigabyte Z390 UD Coffee Lake Chipset BIOS V:F9
RAM: 32GB DDR4-2132 Corsair
Graphics: Radeon RX580 up to date as of 10/18/2021

No other applications running at time of this problem.

If I have left anything off, I apologize ahead of time.
Thank you

Go back to 6.1.26.

.28 introduced a bug in Windows 10 hosts while trying to get ready for Windows 11 hosts.

Had same issue with 6.1.28 update from 6.1.26

Using Windows 10 Home Version 19043
Ubuntu 20.04 LTS machine

Went to 'Turn Windows Features On or Off
Cleared check for 'Virtual Machine Platform'

So far so good, VirtualBox opens normally, and nothing seems to be broken. Guest Additions installed normally.

Pagafantas wrote:'Turn Windows Features On or Off
Cleared check for 'Virtual Machine Platform'

So far so good, VirtualBox opens normally

Yes, With Hyper-V disabled there should be no problem. .28's bug is related to running Virtualbox under active Hyper-V in Windows 10.

Well, I did turn off the Windows feature "Virtual Machine Platform" and "Windows Hypervisor Platform." I rebooted afterwards and tried to open each VM and had the same failure. Scottgus you had mentioned initially to go back to the previous version. I haven't found a method to do that and would appreciate if you could point me to something that tells how that is done? Otherwise I will just uninstall VirtualBox and re-install the last version if that is available still.
Thanks

Hambone_Dad wrote:just uninstall VirtualBox and re-install the last version

That's the method. See https://www.virtualbox.org/wiki/Download_Old_Builds to find the earlier version. Don't forget to synchronise the Extension Pack too.

Thank you Scottgus1. I appreciate the help.