I am still using Korora Linux (and it is great) which is based on Fedora and as such I found the Linux Kernel is updated more frequently than on, say, Linux Mint.
After I upgraded to Korora 22 and I found that my Virtualbox would mysteriously stop working with this dreaded cryptic error being the reason. I could not understand why the kernel driver was suddenly not installed.

Kernel driver not installed

I tried using Yum or dnf to fix the issue. I reinstalled Korora and it was back again for about a month.

But this time when it started showing the error messages I noticed that the Linux Kernel had updated in the last set of updates.
I started doing some research and found very little tied to the error message kernel driver not installed or rcvboxdrv setup.

These notes are more for myself, if you choose to follow it, then it is at your own risk.

Through, research and some trial and error I pieced together a routine of completely de-installing and then re-installing the Virtualbox.
I then found how to reduce the frequency of the kernel being updated by going to

/etc/dnf/ opening  dnf.conf in a text editor and adding a line exclude=kernel*.
not updating the kernel could cause security holes, so I do update but just not with every Kernel update.

As root I added  the following to the dnf.conf file

exclude=kernel*

You should back up any data prior to doing the following steps.

Steps are:

remove virtualbox

cd /etc/yum.repos.d/

dnf remove VirtualBox-5*      <-requires sudo

rm -rf virtualbox.repo            <-requires sudo

sudo dnf update

reboot computer

Add the virtualbox repository back

cd /etc/yum.repos.d/

sudo wget http://download.virtualbox.org/virtualbox/rpm/fedora/virtualbox.repo

sudo dnf update

sudo dnf install binutils qt gcc make patch libgomp glibc-headers glibc-devel kernel-headers kernel-devel dkms

sudo dnf install VirtualBox-5.0

Start VirtualBox