Ohio Rev. Code § 303.122: Limitations on procedural challenges.

No action challenging the validity of a zoning resolution or of any amendment to such a resolution because of a procedural error in the adoption of the resolution or amendment shall be brought more than two years after the adoption of the resolution or amendment.

No action alleging procedural error in the actions of a county board of zoning appeals in the granting of a zoning variance or conditional use certificate as provided for in sections 303.14 and 303.15 of the Revised Code shall be brought more than two years after the variance or certificate was granted.