Ohio Revised Code Title LVIII. Trusts § 5817.11

(A) Unless the will or trust is modified or revoked, and except as otherwise provided in this section, no person may contest the validity of a will or trust that is declared valid in a proceeding pursuant to this chapter.

(B) The failure to name a necessary defendant under division (A) of section 5817.05 of the Revised Code is not jurisdictional. A declaration of a will's validity under this chapter shall be binding upon all defendants who were named or represented, and properly served pursuant to division (A) of section 5817.07 of the Revised Code, notwithstanding the failure to name a necessary defendant. However, if a person is one who should have been named a party defendant in the action in which the will was declared valid and if the person was not named a defendant and properly served in that action, that person, after the testator's death, may contest the validity of a will declared valid.

(C) The failure to name a necessary defendant under division (A) of section 5817.06 of the Revised Code is not jurisdictional. A declaration of a trust's validity under this chapter shall be binding upon all defendants who were named or represented, and properly served pursuant to division (B) of section 5817.07 of the Revised Code, notwithstanding the failure to name a necessary defendant. However, if a person is one who should have been named a party defendant in the action in which the trust was declared valid and if the person was not named a defendant and properly served in that action, that person may contest the validity of a trust declared valid.

(D) In determining whether a person was a party defendant and properly served in an action to declare a will or trust valid under this chapter, the representation rules of Chapter 5803. of the Revised Code shall be applied, and a person represented in the action under those rules is bound by the declaration of validity even if, by the time of the testator's death, or the challenge to the trust, the representing person has died or would no longer be able to represent the person to be represented in the proceeding under this chapter.