Wyo. Stat. § 17-29-903: Proper plaintiff.

(a) Except as otherwise provided in subsection (b) of this section, a derivative action under W.S. 17-29-902 may be maintained only by a person that is a member at the time the action is commenced and remains a member while the action continues.

(b) If the sole plaintiff in a derivative action dies while the action is pending, the court may permit another member of the limited liability company to be substituted as plaintiff.