765 ILCS 1090/18

(a) A receiver is entitled to all defenses and immunities provided by law of this State for an act or omission within the scope of the receiver's appointment. (b) Approval of the court that appointed the receiver must be obtained before the commencement of an action or proceeding against the receiver or a professional engaged by the receiver regarding an act or omission in administering receivership property. (c) A party or party in interest may conduct discovery of the receiver concerning any matter relating to the receiver's administration of the receivership property after obtaining an order authorizing the discovery.