After last Ubuntu 16.04 kernel update (4.13.0-26), Virtual Box stopped working correctly. When starting a virtual machine, the host stops completely. Here are the steps to solve it.
- Remove any previous virtualbox installation (VM's are kept):
sudo apt-get remove virtualbox virtualbox-5.1
- Remove virtualbox-dkms:
sudo apt-get remove virtualbox-dkms
- Add the Oracle repository