Why did France's first postwar tank last just 2 months in service?

Why did France's first postwar tank last just 2 months in service? On 14 July 1951, 10 tanks weighing close to 50 tonnes each rolled down the Champs Elysees with 90 mm guns and 120 mm frontal armour. It was the only time the French public ever saw the ARL 44 move. The design had been drawn in secret between 1940 and 1944 by a clandestine bureau near Sarlat, funded by the technical services of the Vichy government and hidden behind contracts for trolleybus frames, airfield snowploughs and tracked tractors for the Sahara. Four years of hidden work produced a full-scale wooden mockup and nothing that could move or fire. In late 1944 the war ministry ordered between 500 and 600 machines before a single prototype existed. Within a year the figure was cut three times, to 200, then 150, then 60. The chassis dated from 1935, the 90 mm gun came from a naval mounting, and the only engine available was the Maybach HL 230 recovered from dismantled Panther production lines in Germany. The first prototype ran at Le Bourget in March 1946, firing trials opened on 27 June 1947, and by January 1951 the entire fleet was forbidden to fire live rounds because of a defective breech lock. The 503rd combat tank regiment, running 17 captured Panthers, took delivery in October 1951. Two months later the tank was withdrawn from the regiments. On 20 December 1954 the army approved the disposal of the surviving hulls, 14 years after the first drawings were made in hiding. Not one of the 60 vehicles built at Rueil ever fought. Music: Eyes of Glory by Aakash Gandhi, Duty Calls by Rod Kim. Photos: archive.org, publicly available material. 0:00 10 tanks down the Champs Elysees 4:57 Vichy pays for a hidden tank 9:44 Hunting Panther engines across Germany 14:49 A grounded gun and 17 Panthers 20:01 Withdrawn after 2 months, scrapped 1954