The VirtualBox Guest Additions gives a performance boost and extra features to your hosts. Follow these steps to install this package on a GUI-less Ubuntu server guest.

If you cannot upgrade Guest Additions on a VirtualBox VM and instead see a VERR_NOT_FOUND error, take these steps to fix the issue.

If Seamless Mode option is grayed out or not working in VirtualBox, you need to install Guest Additions image and disable 3D Acceleration.