Nautilus won't launch [16.04]

For me terminating the running nautilus process and restarting it worked.

ps awx | grep nautilus

I found the process id and then terminated it with

sudo kill -TERM <id>

The schema org.gnome.nautilus.preferences is defined in the file /usr/share/glib-2.0/schemas/org.gnome.nautilus.gschema.xml which is in the package nautilus-data. Maybe it got damaged somehow.

Use

sudo apt-get install --reinstall nautilus-data

to install that package again.

killall nautilus

will kill all instances.