Basically there is an error in Sudirman Cup (mixed team championships) points, one of the earliest tournament where players can play for Paris ranking points. Corvee/Labar thought they are ahead of fellow French the Popov brothers (their ranks are close but not high enough so only 1 can go), but it was not until the last week of the qualifying period that BWF realized their mistake in Sudirman Cup points (about 10 months after it's done) and quickly adjusted the points which made the Popov lead by 29 points. To make it worse, there are no tournaments left and suddenly Corvee/Labar cannot go to the Olympics.
The French federation nominated the Popovs per the regulations, while Corvee/Labar appealed to CAS. CAS ruled in favor of them and BWF is asked to give an exemption to Corvee/Labar as the 17th pair to play in men's doubles