John Wycliffe's main three criticisms of the Church is:
Wealth of the clergy, authority of the pope, and teaching transubstantiation.
For the information of the one reading this, John Wycliffe was a theologian and also a Biblical Translator. In this case, he was able to give the three criticisms of the Church for he is obtaining the title of being a theologian which indeed studies the nature of God and religious belief.
Answer is Wealth of the clergy, authority of the pope, and teaching of transubstantiation
