Draftsight is easily the best 2D CAD software available on Linux.
Every time there is a new version of an OS, it is very likely that many of the tools you often use might not be compatible out of the box anymore.
After some googling I finally managed to get a proper solution for the Draftsight missing dependencies from an Italian blog.
The fix for Ubuntu 16.04 is:
sudo apt-get install libgstreamer0.10-0 libgstreamer-plugins-base0.10-0
And for Kubuntu:
sudo apt-get install gstreamer0.10-pulseaudio