Virtualbox 5.2.12 - Host Ubuntu 16.04 with a Guest Ubuntu 18.04 - Getting Guest Additions working after update.

I wanted to experiment with Ubuntu 18.04 before I committed to it on my production machine so I installed it on a virtual machine using Virtualbox. My HOST system is Ubuntu 16.04 and the Ubuntu 18.04 is the GUEST. Everything was going fine until Virtualbox upgraded to 5.2.12.

Usually when Virtualbox upgrades it prompts you to upgrade your GUEST ADDITIONS which gives you better screen resolutions, shared clipboards, seamless mode and other very useful stuff. My Windows 10 GUEST did just this and worked just fine, however the Ubuntu 18.04 GUEST would not Mount the Guest Additions ISO.

The solution I found was to install the Guest Additions via the Terminal (Command Line) in the Guest Ubuntu 18.04. Once again RUN THESE TERMINAL COMMAND IN YOUR GUEST UBUNTU 18.04 not you host Ubuntu 16.04.


sudo apt-get update

sudo apt-get install virtualbox-guest-dkms


After running these two commands on the GUEST 18.04 just restart the GUEST and you should be good to go.

If this does not work for you, here are some more suggestions.