The certification to the state treasurer as to the amount payable in any year for debt service on such qualified bonds shall be fully conclusive as to such qualified bonds from and after the time of issuance of such qualified bonds, notwithstanding any irregularity, omission, or failure as to compliance with any of the provisions of this chapter with respect to such qualified bonds; provided, however, that such qualified bonds contain a recital to the effect that they are entitled to the benefits of the provisions of the Qualified Bond Act. All persons shall be forever estopped from denying that such qualified bonds are entitled to the benefits of the provisions of this chapter.
Mass. Gen. Laws ch. 44A, § 9