VirtualBox has been working on this Ubuntu host for years.
Now after the do-release-upgrade from 20.04 to 20.10 it is having a trouble:
sudo apt install linux-headers-$(uname -r)
Reading package lists... Done
Building dependency tree
Reading state information... Done
linux-headers-5.8.0-31-generic is already the newest version (5.8.0-31.33).
linux-headers-5.8.0-31-generic set to manually installed.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
sudo apt install virtualbox virtualbox-dkms
[sudo] password for stephen:
Reading package lists... Done
Building dependency tree
Reading state information... Done
virtualbox is already the newest version (6.1.14-dfsg-4).
virtualbox-dkms is already the newest version (6.1.14-dfsg-4).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
stephen@acer:~$ vboxmanage list vms
WARNING: The character device /dev/vboxdrv does not exist.
Please install the virtualbox-dkms package and the appropriate
headers, most likely linux-headers-generic.
You will not be able to start VMs until this problem is fixed.
