Banning Masks
Despite the fact that the Feast of Fools was a huge party with no rules, people still chose to wear masks in order to hide their identities. That meant that they let themselves act even crazier, including singing obscene songs and throwing dice in churches. The Church realized that masks let people act more rowdy, so they decided to ban masks during celebrations.
Ultimately Banned
Eventually, the Catholic Church felt that the Feat of Fools grew so extravagant that it became blasphemous. It was quite difficult for the Church to completely ban the wildly popular celebrations, but that did not stop them from trying. They officially banned the party in the 1400s, but it would take a least another century for the parties to stop.