Booting From a USB Flash Drive Issues

[dsooz]

Hello!
I've been scratching my head about this one for a while, so any help would be appreciated. I have the following error from a Guru Meditation pop-up:
"A critical error has occurred while running the virtual machine and the machine execution has been stopped"
With other text below that I'm sure everyone has seen before by now.

Here's some info about what I'm trying to do:
- My host machine is Windows 10, running VirtualBox 6.1.16
- I'm trying to boot into a USB flash drive with 64-bit Ubuntu on it using Pendrivelinux's "boot-a-usb-flash-drive-in-virtualbox" guide (I would link it but I haven't been a forum member long enough, sorry)
- I looked through forums first and I'm certain I have VT-x enabled and Hyper-V is turned off (I have a regular 64-bit Ubuntu VM that I also use and works just fine, currently powered off)

I attached the logs that look relevant, and the PNGs are just blanks screens so I didn't include them. I figure the problem has something to do with me trying to boot into the USB, but I'm having trouble figuring out what exactly is going wrong.
I'd appreciate any help! If not I'll just boot into the USB from startup like a regular human being.
Thanks!

[scottgus1]

You're doing the 'fake a USB drive as a regular drive' workaround for Virtualbox's not being able to boot from USB in BIOS boot mode, which uses raw disk access.

Raw disk access on a Windows host requires Virtualbox to be run as Administrator. The physical disk being raw accessed must be offline in the Disk Management console. You have to be sure you're raw-accessing the correct disk.

Hyper-V is off, and the VM guru-meditates just after it initializes and attempts to read the disk.

Check that you are running Virtualbox as Admin and the disk is offline. Also consider that Virtualbox is supposed to boot from USB using the EFI boot mode, though the OS to be installed also needs to be EFI-ready.

[dsooz]

I have been running VirtualBox as admin, and the OS supposedly supports UEFI (which I think should suffice, but I might be wrong), but I just checked the Disk Management console as you mentioned:

The physical disk being raw accessed must be offline in the Disk Management console

And it appears that the flash drive is removable storage and unfortunately can't be marked as offline, so I bet that's where the problem is coming from.
Thanks for the heads up! I might just have to boot into the flash drive on startup from now on.