1.14.4 Make Passive mobs attack

Hello everyone i am trying to make my custom sheep to attack any creature or monster nearby. i added couple of pathfinders. in game sheep approaches its target but after it attacks, server crashes due to 'IllegalStateException'. Any help would be great. Thanks in advance

this is my sheep class mentioned

Code (Text):

public class CustomSheep extends EntitySheep{

    public CustomSheep(EntityTypes<? extends Entity> entitytypes, World world) {
        super(EntityTypes.SHEEP, world);
     
        Sheep customSheep = (Sheep) this.getBukkitEntity();
     
        this.goalSelector.a(1, new PathfinderGoalMeleeAttack(this, 1.0D, true));
        this.targetSelector.a(0, new PathfinderGoalNearestAttackableTarget(this, EntityCreature.class, true));
        this.targetSelector.a(1, new PathfinderGoalNearestAttackableTarget(this, EntityMonster.class, true));
     
        this.getWorld().addEntity(this);
    }

}