What did Desiderius Erasmus criticize in his theological works?

He criticized aspects of society that he believed most needed reform. He singled out monks for special treatment ... sought reform in the Catholic Church, but he didnt want to break away from it.

I think Desiderius Erasmus mostly criticized corruption in the Church in his theological works.

He believed that over time, the Church became corrupted and thus he wanted to reform it through his work. Even though he saw the corruption in the Church, he never had the courage to actually break away from it, at least not officially.