Ohio Rev. Code Ann. § 519.121

All amendments or supplements to a township zoning plan adopted by a board of township trustees prior to the effective date of this act, except those amendments or supplements which a court of competent jurisdiction has declared unlawful or unreasonable or which are the subject of an action now pending in such a court, are hereby ratified and shall be valid amendments or supplements to such zoning plan regardless of the procedure followed with respect to such amendments or supplements prior to their adoption by a board of township trustees, except that no right of appeal on the issue of the unlawful or unreasonable character of an amendment or supplement shall be lost by the provisions of this section.