The very nature of the adverse forces, are to fight against the Light. I suppose one can say that they know what it represents, but they fight against it.
Ultimately, there is only Love, and darkness is only a lesser form of Light or Love. The adverse or wrong forces fight against the Light, and God may sanction, tolerate or approve. He may also feel bad, perhaps, as the wrong forces entering can be a setback for the Soul.
Still, one cannot really say that there are mistakes in God's plan. He is the Doer; the act being done and the enjoyer Supreme. Another nice question.