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. Look up instructions for how to unblock an application from the firewall for your OS.