[Drizzy]

    private void GroupBuff(Player player, List<Integer> list){ 
        Summon pet = player.getPet(); 
        Skill skill = null; 
        if(player.getEffectList().getEffectsBySkillId(Skill.SKILL_RAID_CURSE) == null) 
            player.getEffectList().stopAllEffects(); 
        if(player.getPet() != null) 
            player.getPet().getEffectList().stopAllEffects();

Тыкну вам пальцем на ошибку, а дальше думайте