main reason: having installed virtualbox before, there are multiple virtualboxes in the system. You can uninstall all virtualboxes first, and then install
again
. Uninstall all virtualbox:
sudo apt-get autoremove 'virtualbox*'
2. Reinstall:
sudo DPKG -i virtualbox – 5.2 _5. 2.6-120293 ~ Ubuntu ~ xenial_amd64. Deb p>