"I like when it is easy."
Translation:J'aime bien lorsque c'est facile.
The English doesn't make sense to me. Shouldn't it be "I like it when it is easy"?
No. It is fine either way. In this sentence, "like" is a transitive verb. In "I like when it is easy," "when it is easy" is the direct object. In your suggestion, "when it is easy" is what we call an object complement renaming "it," the direct object.
I don't see why it has to be j'aime bien. Isn't that I like a lot or something extra?