Okay, in 1002, Robert the Pious, King of France, was excommunicated by the pope for marrying his cousin (I think). I'm not sure what effect this had on him OTL, but if, say, he devotes the rest of his life to becoming a good Catholic again and abdicates to join a monastery, what would happen next?
Otto-William of Burgundy is the closest heir (Robert had no kids), so I'm pretty sure that he'd be the one to technically inherit the throne. How will the bigger, stronger French duchies take this? What happens to Brittany, Normandy, and Burgundy?