Neb. Rev. Stat. § 21-166

(RULLCA 903) (a) Except as otherwise provided in subsection (b) of this section, a derivative action under section 21-165 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.