Father appealed from a final order vacating dependency of the minor children and appointing guardians. Father claimed that the order was void because of a procedural error committed 18 months earlier, when a referees dispositional order on a supplemental 387 petition was not countersigned by a judge as required by section 249. The appellate court here affirmed. Fathers challenge to the removal order was barred by the waiver rule. His failure to make the challenge on direct appeal in June of 1999 forecloses raising it on appeal from a 366.26 order held over 18 months later.