What were some of Catherine the Great's failures?

One of her failures was allowing the boyars to increase their stranglehold on Russian peasants. She took firm action to repress the peasants when they revolted against the harsh conditions of serfdom. As a result, conditions grew worse for the peasants, and even more were forced into serfdom. The fact that she kept serfdom alive while it was dying out in other places put Russia at a disadvantage in world affairs.