Font Viewer not running in Ubuntu 16.04

I edited the .desktop file as a workaround:

sudo sed -ir 's/^\(DBus\)/#\1/' /usr/share/applications/org.gnome.font-viewer.desktop

Normally I advise against changing package owned file under /usr/share, since such changes will be overridden at next update of the package in question. However, in this case the issue is about to be fixed with the next update of the package, and it will start working again without workarounds.

The fix for this has been released, please run

sudo apt dist-upgrade

Open a terminal with CtrlAltT

Issue the following commands:

sudo apt-get update
sudo apt-get upgrade
gnome-font-viewer --display=:0

As an alternative you could create a desktop shortcut for it.

One way to do this is to use the old gnome-desktop-item-edit.

First you'll need to install is with sudo apt-get install gnome-panel

Next issue the command `gnome-desktop-item-edit --create-new ~/Desktop

Fill out the fields as shown:

It worked for me.

Source: Experience