Ohio Rev. Code § 2309.59
In every stage of an action, the court shall disregard any error or defect in the pleadings or proceedings which does not affect the substantial rights of the adverse party. No final judgment or decree shall be reversed or affected by reason of such error or defect. In the judgment of any reviewing court upon any appeal in any civil action, when it is sought to reverse any final judgment or decree or obtain a new trial upon the issues joined in the pleadings, the reviewing court shall certify on its journal whether, in its opinion, substantial justice has been done the party complaining, as shown by the record of the proceedings and final judgment or decree under review. If the reviewing court determines and certifies that, in its opinion, substantial justice has been done to the party complaining as shown by the record, all alleged errors or defects occurring at the trial shall be deemed not prejudicial to the party complaining and shall be disregarded, and the final judgment or decree under review shall be affirmed, or it shall be modified if, in the opinion of such reviewing court, a modification of it will do more complete justice to the party complaining. If the reviewing court determines and certifies that, in its opinion, substantial justice has not been done to the party complaining as shown by the record, such court shall reverse the final judgment or decree and render, or remand the case to the lower court with instructions to render, the final judgment or decree that should have been rendered.
R.C. §2309.59