N.D. Cent. Code § 28-32-13

A rule is invalid unless adopted in substantial compliance with this chapter. However, inadvertent failure to supply any person with a notice required by section 28-32-10 does not invalidate a rule. Notwithstanding subsection 2 of section 28-32-42, an action to contest the validity of a rule on the grounds of noncompliance with this chapter may not be commenced more than two years after the effective date of the rule.