Cannot change the ReversedRelationType for %1: the target ReversedRelationType %2 already has a ReversedRelationType %3. ...

Cannot change the ReversedRelationType for %1: the target ReversedRelationType %2 already has a ReversedRelationType %3. Make change to %2 instead. (If both have itself as the reversed, then you must set the reversed to nothing first, then modify the other.)