That far along it could be the float test? Maybe dropped their temp too long? That's the thing about the humidity it carries the heat, but it carries it away too. So the 20 minutes to an hour they could make it out of the incubator could be basically nothing if they are wet. Sometimes they just don't go for whatever reason. I'm no expert, about 15 runs. Typically I do about 50 at a time, it seems like there is always at least one that looks completely viable, it just didn't make it. Sometimes quite a few more. If there isn't one dud left under a hen hatching it's lucky. Hopefully you'll have better luck next time.