Comment # 2 on bug 1045871 from Larry Finger

Recent TW releases stopped doing the automatic conversion of SysV init.d
scripts into systemd services for VirtualBox. As a result, VB failed to start
as you noted. Rather than trying to resurrect this legacy method, new service
files were created and startup was moved away from the SysV scripts.

There is a new version of VirtualBox being built that solves this problem.
Unfortunately, I cannot predict how soon it will reach TW. If you want to try
it before the build process finishes, copy the files from
http://www.lwfinger.com/virtualbox into a directory on your hard drive, use
YaST "Software Repositories" to add that directory as a "Local Directory", and
then use "Software Management" to update VB with those files. Search for
"virtualbox", click on the Versions tab, and select the new repository. You
will not need to replace the "host-kmp" package, but the others should be
updated. After reboot, VB should be started.