MacBook Pro's Trackpad stops working when connecting an external keyboard I'm trying to set up a new Ergodox EZ keyboard. Whenever I plug in the keyboard's via USB port, the MacBook's built-in Trackpad ceases to function. It responds to absolutely no input at all. This makes it impossible to configure the keyboard properly (I have to go through a wizard so the computer can figure out the keyboard uses an ANSI layout).

If I disconnect the keyboard temporarily, I can press next, plug the keyboard back in, and then continue with the wizard, but at the final screen I need my mouse again. So I have to disconnect → click → reconnect, at which point the wizard reappears from the beginning claiming that the keyboard could not be identified.

This is preventing me from successfully configuring the keyboard. How do I fix this?
It's possible that plugging in the keyboard is causing macOS to detect a cursor control device (mouse).

Go to System Preferences app → Accessibility → Mouse &amp; Trackpad and check if Ignore built-in trackpad when mouse or wireless trackpad is present is checked?



If it is, simply uncheck and try again. You should now be able to use the built-in Trackpad normally while your keyboard is plugged in.