If you're trying to run virtual-box machine and you're getting this error:

Kernel driver not installed (rc=-1908)  Make sure the kernel module has been loaded successfully.  where: suplibOsInit what: 3 VERR_VM_DRIVER_NOT_INSTALLED (-1908) - The support driver is not installed. On linux, open returned ENOENT.

Run following command and your problem should be fixed.

sudo kmutil load -p '/Library/Application Support/VirtualBox/VBoxDrv.kext'

You can reboot your system and it should be working now.

Also remember better way is always to keep your virtual-box updated.