RTR3InitEx failed with rc=-1912 (rc=-1912)

[Bob]

After an update I now get the error massage "RTR3InitEx failed with 
rc=-1912 (rc=-1912)" when I try to start a virtual machine.

The VirtualBox kernel modules do not match this version of VirtualBox. 
The installation of VirtualBox was apparently not successful. Executing

'modprobe vboxdrv'

may correct this. Make sure that you are not mixing builds of VirtualBox 
from different sources.

where: supR3HardenedMainInitRuntime what: 4 
VERR_VM_DRIVER_VERSION_MISMATCH (-1912) - The installed support driver 
doesn't match the version of the user.


Running "modprobe vboxdrv" does not fix the problem.

I tried to reinstall Virtual using "sudo apt remove virtualbox" "sudo 
apt install virtualbox" which did not fix it.

Searching the internet the fix is to install VirtualBox from Oracle.  I 
tried to do that but have not had success.  I have never tried to 
install anything except from Ubuntu.  What is the proper way to install 
things from other sources?