Happens in every single one of my games. I haven't seen a successful France in a long time. Even if they start out strongly and unite their own territories, they always - and I mean always - end up at war with Aragon, Burgundy, England and Austria at the same time, send all their troops to Aragon, and then get completely occupied by a combination of the other three. Then they're forced to release their minors and cede huge amounts of land to England and Burgundy.
I really wish that, just once, I could see a successful France. That would be a strange screenshot.
The best way to see that would be is Paradox would either remove some of the small French vassals they have so many of since DW, or to add an event for France that removes the Vassal cores upon annexation (or does it already have that; can't remember). I know it's something of a tradition to add a new French vassal in each new expansion, but it's really messed up the game balance.