I recently updated to Fedora 29 (release version) but the Nautilus integration stopped working, even after doing sudo dnf remove insync-nautilus ; sudo rpm -i insync-nautilus-1.3.12.36116-fc17.noarch.rpm.
The Insync right-click menu entries are missing, as well as the sync badges on the file/folder icons. I’m running GNOME nautilus 3.30.2.
This sadly does not solve the issue, which is more likely to be in the insync-nautilus-1.3.12.36116-fc17 package. What I’ve noticed is that there are some “print NNN” statements that should be “print (NNN)” in /usr/share/nautilus-python/extensions/insync_plugin.py. I’ve corrected these, but the integration still does not work.