Sec. 17. Except as provided in section 16.5 of this chapter, any interested person may contest the validity of any will in the court having jurisdiction over the probate of the will within three (3) months after the date of the order admitting the will to probate by filing in the same court, in a separate cause of action, the person's allegations in writing verified by affidavit, setting forth:
(1) the unsoundness of mind of the testator;
(2) the undue execution of the will;
(3) that the will was executed under duress or was obtained by fraud; or
(4) any other valid objection to the will's validity or the probate of the will.
The executor and all other persons beneficially interested in the will shall be made defendants to the action.