Good find! I've been messing around with controller stuff and pushed the build out rather quickly.
Couple questions to help me narrow this down:
Did you have a controller plugged in? If so, what kind?
Did you play any previous version of the game? (literally any version)
Does deleting your save data do anything? (go to AppData, Local, KNOCKOUT ARCADE test. You should see 2 files named 1PlayerControls and 2PlayerControls)
I really appreciate you letting me know about this. Crashes are the not too uncommon in this project lol.