Unity user interface for a Ubuntu Linux VMWare virtual machine

3D acceleration might not be working for your virtual machine. By default Unity is looking for it. If you want to have it anyway, activate the 2D version of it.

Here are the commands:

$ sudo add-apt-repository ppa:unity-2d-team/unity-2d-daily
$ sudo apt-get update
$ sudo apt-get install unity-2d-default-settings

 For more information, have a look here.