Have you encountered this kind of problem when using VirtualBox on Ubuntu?
Kernel driver not installed (rc=-1908) The VirtualBox Linux kernel driver (vboxdrv) is either not loaded or there is a permission problem with /dev/vboxdrv. Please reinstall the kernel module by executing '/etc/init.d/vboxdrv setup' as root. If it is available in your distribution, you should install the DKMS package first. This package keeps track of Linux kernel changes and recompiles the vboxdrv kernel module if necessary.
If yes, here I share with you the solution.
First, install the linux headers:
sudo apt-get install linux-headers-`uname -r`
Reconfigure dkms and load module:
sudo dpkg-reconfigure virtualbox-dkms sudo modprobe vboxdrv
Then VirtualBox works. No computer reboot needed.