Normally, when I upgrade from one version of Ubuntu to another, my virtual box virtual machines survive the upgrade.
However, after upgrading from 14.04 to 14.10, they did not. I submitted a bug here, which provides this screenshot.
Anyway, I'm not sure I understand how to get this back going again. I uninstalled virtual box and reinstalled it like this:
sudo apt-get remove virtualbox ; sudo apt-get install virtualbox
This didn't achieve anything. It seems like the fix is more involved than this. Please advise.
This answer is a self answer that the OP has posted as an "update" section in the question.
(@LonnieBest If you post a real self answer, leave a comment on this, and I delete it.)
Thanks to this post, I fixed this with the following command(s):
(took effect after reboot)
I had a similar issue. However my kernel was the current version. The resolution to my problem was to go to Virtual Box site and download and run in Virtual Box the current extension pack.