Ohio Revised Code Title VII. Municipal Corporations § 713.121

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

No action alleging procedural error in the actions of an administrative board created under section 713.11 of the Revised Code, or of any other administrative entity acting under that section, in the granting of zoning variances or conditional use certificates shall be brought more than two years after the variance or certificate was granted.