Background
I'm on VirtualBox 6.0.12. I had a drive which contained a /boot partition, and an encrypted (LUKS) main partition. I wished to remove the encryption and apparently the best way to do this was to migrate Ubuntu to a new drive.
Prior Actions
I used this answer to move the partition contents. I moved both /boot and the main / partition contents. As far as I can tell, it moved it just fine.
https://askubuntu.com/a/741727/128596
As part of step 5 of the above answer, I used the steps below through used of a live CD (no errors reported).
https://askubuntu.com/a/88432/128596
After doing this it seems to boot the Ubuntu partition okay, but got stuck at the (basic looking) Ubuntu 4 dot loading screen (like this one but with 18.04 text).
When I got stuck there, I looked to other answers and I tried to run boot-repair from the live CD but I just got back to the 4 dot loading screen.
Later Events
If I wait for long enough I get dropped to an initramfs screen, and upon trying to exit it I get this behaviour.
Playing around with enabling/disabling 3D acceleration and changing VirtualBox graphics driver don't seem to work.
Question
What actions, if any, can I take to fix this?
