I performed a dist-upgrade and then and autoclean and autoremove. It disabled the Virtual Box service on Linux because the headers were out of date. The headers caught up, so I rebuilt the modules off the Guest Additions CD.
I'm trying to start the service again, but I can't seem to find the command. For example, I found How to automatically start and shut down VirtualBox machines?, but it talks about using the Virtual Box manager and not Ubuntu's service control.
How do I start How to start Virtual Box service on Ubuntu Linux?
If needed, how do I reinstall the Virtual Box service on Ubuntu Linux?