Utah Code § 16-19-903: Proper plaintiff.

A derivative action to enforce a right of a limited partnership may be maintained only by a person that is a partner at the time the action is commenced and:

(1) which was a partner when the conduct giving rise to the action occurred; or

(2) whose status as a partner devolved on the person by operation of law or in accordance with the terms of the partnership agreement from a person that was a partner at the time of the conduct.