Whonix-CLI-15.0.0.9.4 gateway shows a black screen?

I just imported Whonix-CLI-15.0.0.9.4 for Virtualbox and when I start the gateway, I simply get a black screen.

It shows the Spectre mitigation and that sda is clean, then I get the black screen.

ACPI shutdown in virtualbox works.

What is wrong? What should I do?

I found that adding nomodeset fixes my problem, however, how do I add this so it is permanent? There is no /etc/grub/default file, where should I add this?

Edit:

See Kicksecure ™ in VirtualBox - Troubleshooting - Kicksecure ™ does not Start?


rob75 via Whonix Forum:

I found that adding nomodeset fixes my problem, however, how do I add this so it is permanent? There is no /etc/grub/default file, where should I add this?

Documented just now:

Also Self Support First Policy for Whonix applies.