The Old Regime collapsed because it was unable to reform itself.
The problems of the OIld Regime necessitated projects to reform throughout the 1780's whilst utimately the Regime collapsed, it did so becuae it was not capable of undergoing change.
For the 50 years preceding the French Revolution in July 1789, France had been though many wars which had left it with great financial debts. The American War of Independence which ended in 1783 was the last war from which France was recovering and it had put the Regimne further into debt. Loans taken out during the war were now requesting 40% of the Government's income. However, exceaaive spending of the Court, inadequate tax collection from the privileged Estates made it impossible to overcome the debts. As the Controller General Callone found out the Government became bankrupt. Simon Schamna points out that it appeared as if there were no finances with which to pay interest on the loans.The task that Calonne had in front of him was to reform Frence's finances.
The Regime tried to instigate reforms into this key sector of Government. A member of Controller Generals confronted Louis XVI that reforms were necessary and he seemed to agree to this. His willingness may have been there but they were unable to go through with them as those who would have been responsible for the reform were incompetent.
The total feudal system of France was the reason causing the major problem for the Government. The fact was that the taxes which sould have been paid by the Nobility, were not done and therefore half of the Government';s income became diminished.
The Church was even more at fault as they were paying no tax, but only giving a gift to the Government, a " donm gratuit " which was never even close to what it should have been.Instead of the privileged classes, the burden fell on the peasants.They had to pay taxes es well as rent to the Nobility and tithes to the Church.