Problem: Despite the insync process running the Insync Custom Icons not displaying in Nautilus under Gnome Shell in Fedora 20.

Cause: nautilus-python core dumping when attempting to load  insync_plugin.py (which is what enables the custom icons)

Resolution: Install the latest version of nautilus-python

su -c 'yum update --enablerepo=updates-testing nautilus-python-1.1-6.fc20'