I wanted to use VNC to allow multiple desktops on a server.
In Ubuntu 16.04 (or 14.04, 17.10 or Linux Mint Cinnamon) I found that neither the GNOME desktop nor the XFCE desktop would work with VNC - I tried vnc4server, realvnc, and tigervnc. They all crashed in slightly different ways, but each was unuseable.
The solution, which so far I've tested in Mint and 16.04 with tigervnc, is just to make sure you uninstall the default vino desktop sharing tool before installing tigervnc. Simple!