After upgrading from 14.04 to 16.04 I encountered the following when trying to run TeamViewer:
The TeamViewer daemon is not running!
Then it says to try "teamviewer --daemon start".
When I tried that I got:
systemctl start teamviewerd.service
Failed to start teamviewerd.service: Unit teamviewerd.service not found.
To fix this I ran the following command after some research:
sudo cp /opt/teamviewer/tv_bin/script/teamviewerd.service /lib/systemd/system/
Now it works.