Yeah, it's a load in some included script.
var icon = load(script_path + "/icons/object.png")
Was just some icon that I stopped using. Everything else was running fine in the built game, so I think I was fixated on the instance that was clearly there, but failing to preload.
One thing that made this difficult to track down was that sometimes when I made certain changes that created more fatal errors, the game would start up and close immediately, so I couldn't get a chance to read the console.
Is there way to suspend or log the debug console on exported games?