This is for Ubuntu 18.04 LTS. TigerVNC is a remote desktop server and viewer solution sponsored by Red Hat that is still in active development. There are packages for it in the repositories of the major distributions, but the latest versions for Ubuntu are broken. My workaround is to use the latest stable version from the TigerVNC project Github release page, where generic binaries for 32 and 64-bit Linux are distributed as tarballs (dmg and exe installers for Mac and Windows are also available).
- Remove any pre-existing vnc software, like RealVNC 4:
$ sudo apt remove --purge vnc4server xvnc4viewer
$ sudo aptautoremove