Modifier Keys not working for swapping Option/Command on external USB Keyboard I have been using the Modifier Keys option for a few years. It is however not working on Sierra for external keyboards.

The screenshot shows the configuration:



I have exited System Preferences and only on Sierra this does not take effect.  The laptop has been rebooted a few times as well: still no change.

I have tried this for several external keyboards from different manufacturers and on two different Sierra laptops.  

Anyone have a workaround?
Karabiner Elements to the rescue:



This actually works!