Nautilus won't launch [16.04]
Solution 1:
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>
Solution 2:
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.
Solution 3:
killall nautilus
will kill all instances.