Cannot delete the exchange target

HI

So far migration is almost complete. we migrated from 9.0.4 to 10.0.3. Therefore right now is the time for clearance. So we want to delete the old exchange target on EV site but we got error "Could not delete the exchange archiving target, NULL" at the same check Event Viewer got error 13360.

If anyone had faced this kind of problem would appreciate if can share with me. millions thanks !!! :)