“The overriding consideration on a motion to set aside an order dismissing an appeal is the justice of the case, which entails a consideration of the merits of the appeal: Akagi v. Synergy Group (2000) Inc., 2014 ONCA 731, at para. 8. In addition, factors analogous to those typically considered on a motion to extend the time to appeal inform a request to set aside the administrative dismissal of an appeal: (i) the explanation for not perfecting the appeal within the time stipulated by the rules; (ii) the length of and explanation for the delay in moving to set aside the administrative dismissal; and (iii) prejudice to the respondent.
More justification must be shown by a party moving to aside an administrative dismissal of an appeal than would have been required had the party earlier availed itself of its rights to move for an extension of time to perfect the appeal: Langer v. Yorkton Securities Inc. (1986), 1986 CanLII 2612 (ON CA), 57 O.R. (2d) 555 (C.A.), at para. 14.”