virtualbox.org

I've seen various people reporting this problem, and there seem to be a variety of solutions, however none that worked for me. I exported my Ubuntu 20.04 VM on VirtualBox 6.1.30 on a Windows 10 host as 1.0 version of .ova. This ova worked on a MacOS host, Ubuntu host, as well as another Windows host, most with 6.1.32 Virtualbox. It failed on quite a few others with the same symptom I see all over the google searches: Ubuntu VM stuck on black screen with a white underscore.

The solution was going to the Settings for the virtual machine (when it is turned off) and setting in the System section under the Acceleration tab the Paravirtualization Interface to "Default". (it had been set to "None")

"Default" is the default btw. So either you changed this yourself or you imported the VM.

Not reflecting a hypervisor API into the VM should not be terminal if the VM is otherwise well configured, likewise not reflecting the correct hypervisor API (e.g. reflecting a KVM API into a Windows VM). It should only mean that the VM loses the benefit of the API. So I think there may be some other factor at play here, like overcommitting RAM or CPU.