65540: Invalid scancode -1 logged in key bind menu when an option is unbound

When opening the key bind menu with any option unbound the following is logged:

########## GL ERROR ##########
@ Render
65540: Invalid scancode -1 

This happens once when the game first loads and the menu is opened, and only happens again once the game is restarted and the menu is opened and scrolled through to where an unbound option is present.