TypeError: Cannot read property 'async' of null

[sellout]

When I click “FLASH KEYBOARD” with this layout loaded, I get the above error. (NB: that layout hits #224 first, so the layout name needs to be changed to “Atreus-default” before loading.)

The only thing I think is odd about this layout is that there are a number of completely unassigned keys, but unassigning keys from, say, the default layout doesn’t cause this same error.