[Solved] Black screen with underscore when selecting install ubuntu

[Simon Ghoul]

(This is fixed in VirtualBox 6.1.22, thank you guys for fixing it!)

I start VirtualBox 6.1.16, create a virtual machine, insert the ubuntu iso (ubuntu-20.04.1-desktop-amd64.iso), then I start the virtual machine. The virtual machine starts with a purple screen, with icons at the bottom, and then after a short while I get a bunch of options. I select "Install ubuntu", then I get a black screen with an underscore.

I had read many posts related to this and the causes are always different, I have no idea why this is happening. I'll be attaching the logs, but if you need to know the settings or specs let me know (I believe the logs has my settings too, based on what one person on the forums said).
I had enabled hyper v through the Windows Features window (Virtual Machine Platform and Windows Hypervisor Platform). It's also enabled on the bios.
Please note that I want these enabled, it's needed for another product called Bluestacks (it works properly and runs a lot better with them on)

Multiple logs are attached, unsure which one was the most recent

[Simon Ghoul]

I had also used VirtualBox before on a laptop, it worked perfectly. Ubuntu, Kali Linux, Windows 10, they all ran properly.

It has also happened to me that I start Ubuntu and it starts with that black screen with an underscore (or goes to the inital purple screen with the icons at the bottom, then suddenly turns black with a white underscore). I don't have logs on that. I also have an issue where I try to install Windows(Win10_20H2_English_x64.iso) and after installation, I get a blue screen of death. These two may not be related, but I am sharing in case they are and they may give hints in solving this issue (I would like to focus on the first issue, the one on the post above). But again, I have no logs on those and I can try to gather them later if requested (I mean, they take time, and I need my computer right now to finish some work I have to do)

Here are some more attachments

[multiOS]

This from your first Log:

00:00:03.019520 ********************* End of CFGM dump **********************
00:00:03.019563 HM: HMR3Init: Attempting fall back to NEM: VT-x is not available
00:00:03.076636 NEM: WHvCapabilityCodeHypervisorPresent is TRUE, so this might work...

usually means Microsoft's Hyper-V has been enabled, which can (very frequently does) severely impair the performance of VirtualBox. and also other third-party virtualisation applications.

Please see if the recommendations here: viewtopic.php?f=25&t=99390 work for you

[Simon Ghoul]

usually means Microsoft's Hyper-V has been enabled, which can (very frequently does) severely impair the performance of VirtualBox. and also other third-party virtualisation applications.

Please see if the recommendations here:

This worked, thanks. I only had to do step 4, and also only step 2 from the post referenced

[multiOS]

Glad you're working.

I suggest you keep a 'note' of the guide, as updates to the Windows Host (usually only the 6/12 month Feature Updates) can lead to Hyper-V been reactivated. The VirtualBox Developers are continuing their efforts to improve operation/performance with Hyper-V active, so maybe one day.....

[Simon Ghoul]

I bookmarked it

Edit: Shortcuts

bcdedit /set hypervisorlaunchtype off

(Changing the bios was unnecessary for me, it disables it self when I do the above and disable the windows feature I think. It also enables itself when I re-enable things)

Edit2: to enable

bcdedit /set hypervisorlaunchtype auto

(Why? Cus bluestacks hyper-v. This bug is very annoying)