Vt. Stat. tit. 16 § 552
No action shall be brought directly or indirectly attacking, questioning, or in any manner contesting the legality of the formation, or the existence as a body corporate and politic of any union school district created pursuant to chapter 11 of this title after six months from the date of recording in the office of the Secretary of State the certificate of the Secretary of Education designating the district as required by section 706g of this title; nor shall any action be brought directly or indirectly attacking, questioning, or in any manner contesting the legality or validity of bonds, issued or unissued, voted by a school district after six months from the date upon which voters in the school district met pursuant to warning and voted affirmatively to issue bonds to defray the cost of school improvements. This section shall be liberally construed to effect the legislative purpose to validate and make certain the legal existence of all school districts in this state and the validity of bonds issued by school districts, and to bar every right to question the existence of a school district or the validity of a bond voted by it, in any manner, and to bar every remedy therefor notwithstanding any defects or irregularities, jurisdictional or otherwise, after the expiration of the six-month period.
16 V.S.A. § 552