The unwritten constitutional setup of France during the Ancien Regime seems horrendously complex, so it would be great if someone with greater knowledge could enlighten me.
From what I have read the problem the King had with reforming the taxation system was that it was repeatedly blocked by the provincial parlements, who could refuse to register royal edicts in their domains. However, I understand the King had the power to use a lit de justice to force compulsory registrations. Why couldn't Louis XVI do this to fix the French finances before the revolution?