The host system is an iMAC:
macOS Mojave
Version 10.14.5
iMac (Retina 5K, 27-inch, Late 2015)
Processor 4 GHz Intel Core i7
Memory 16 GB 1867 MHz DDR3
Graphics AMD Radeon R9 M395X 4 GB
VirtualBox:
Version: 6.08 r130520 (Qt5.6.3)
VirtualBox 6.0.8 Oracle VM VirtualBox Extension Pack
The virtual machine is Ubuntu 14.04. In the virtual machine I have installed the guest additions:
sudo apt-get install virtualbox-guest-dkms
I restarted the VM after installing this. The problem is that in the System Settings / Screen Display I still only see a resolution of 640 x 480 (4:3) with no option to select a higher resolution.
What haven't I done?