Whonix (downstream) isn’t producing VirtualBox. Oracle (upstream) When there are issues with the VirtualBox host software, in many cases very limited help can be provided downstream. Upstream might have better ideas.
Linux user permissions issue? Try Permission Fix. For non-Kicksecure:
Do not run this when logged in as root. Just echo to show the command it would run. If it makes sense, remove the echo. But before, make sure to have a backup for the whole disk to avoid doing further damage.
echo sudo chown --recursive $(whoami):$(whoami) /home/$(whoami)
Something file might have been corrupted on the host operating system.
(Whonix is based on Kicksecure.)
For data recovery… Even if the VM no longer starts, there’s a good chance the virtual hard drive file can be detached from that VM and that data can be recovered from the virtual hard disk file.
prerequisite knowledge is this chapter:
VirtualBox VMs Folder versus VirtualBox Settings Folder
You could try to move (or delete) the VirtualBox settings Folder. The VirtualBox VMs folder would still exist and contain the virtual hard drives. The VirtualBox hard drive could then be attached to a newly imported Whonix-Workstation.
The question is more about VirtualBox than Whonix. Do not rely on this forum to tell every step. It’s not required and it’s not efficient. By learning how to do it with any other VM = knowing how to do it for a Whonix VM.
What has a good chance - but data loss:
