This error means that the ZeroTier background service on your computer is either not running, or your local firewall is preventing the UI or CLI from talking to it.
Windows 10
Open Task Manager and go to the “Services” tab. Scroll down until you see “ZeroTierOneService”. The status column should say “Running”. If it does not, right click on the line and click “Start”
macOS
Open Terminal.app and execute the following commands
sudo launchctl unload /Library/LaunchDaemons/com.zerotier.one.plist
sudo launchctl load /Library/LaunchDaemons/com.zerotier.one.plist
Linux
If your Linux distribution uses systemd, execute “sudo service zerotier-one start”
If not, execute “sudo /etc/init.d/zerotier-one start”
Still doesn’t work?
Your system firewall is likely blocking communication with the ZeroTier service