Guest OS not starting after upgrade to 6.1.16

[Belgarath]

Hi guys,
Have just upgraded from 6.2.20 to 6.1.16 and now I get an error message when I start up the guest OS.
Error message is as follows:
"Not in a hypervisor partition (HVP=0) (VERR_NEM_NOT_AVAILABLE).
VT-x is not available (VERR_VMX_NO_VMX).

Result Code: E_FAIL (0x80004005)
Component: ConsoleWrap
Interface: IConsole {872da645-4a9b-1727-bee2-5585105b9eed}"

Host OS is Windows 10 Version 19041.685 Guest OS is Windows XP
All was well until I updated to VB 6.1.16
Anybody got any ideas??

[scottgus1]

Either your PC BIOS does not have the "Virtualization Technology" (VT-x/AMD-V/SVM) turned on, or something on the PC, like Hyper-V or 3rd-party antivirus, is interfering. Go through every part of
I have a 64bit host, but can't install 64bit guests

[Belgarath]

Hi again,
Trying a regression as the hardware does not support VT-X etc. Re installed 6.0.20 but of course the extension pack has been upgraded to 6.1.16. How can I get hold of the 6.0.20 extension pack? The website asks that you use the correct extension pack for the installed version but only appears to have the 6.1.16 pack available. This seems a bit unusual as the previous versions of the application are available!

Thanks
Brian

[scottgus1]

On the Virtualbox Downloads page there's a 'Virtualbox Older Builds' link. Each available older build has a matching Extension Pack in that build's section.

[Belgarath]

Many thanks "scottgus1" for the assistance, system is back up and running at Version 6.0.20. I missed the extension link on the "old downloads" page.
Must remember not to upgrade until I get some better hardware.
Brian