Connection
The Connection page doesn't show the controller
- In System Settings → Bluetooth, check that the controller really is paired.
- Bring it closer and press any button to wake it.
- Back on the Connection page, click the refresh button in the top right.
If macOS's Bluetooth list doesn't show it either, the problem is the system pairing. Solve that first; JoyHarness can't stand in for Bluetooth.
Connection
Connect does nothing, and the Joy-Con has been used with a Switch since
Once it has been paired with a Switch, its pairing with this Mac no longer works. Remove it in System Settings → Bluetooth, then hold the small round button on the rail and pair it again.
Permission
It shows connected, but presses do nothing
Usually the controller is being read but the permission to press keys isn't fully granted. Open Settings and check that Accessibility under Permission at the top really is granted.
If the menu bar, battery and connection all look normal and only the presses do nothing, check Accessibility again first.
Status
Responding says Paused
Pausing doesn't disconnect the controller, but no button does anything. Click Resume on the Connection page, or choose Resume from the menu bar's status menu.
Service
Responding says Not running
The part that does the work hasn't started, so the controller won't do anything. Choose Restart JoyHarness from the menu bar's status menu, wait for the status to change, and check that it says Ready to go.
Don't delete the configuration first. A service that isn't running and a mapping that's wrong are different problems; resetting the configuration won't start a stopped service.
Diagnostics
Still not working
Open About and click Export next to Diagnostics. The file holds the version, connection, service and permission status. It contains no recordings and nothing you said.