you use interlude ?
and is realy easy to add that.
just serch for :
if (getSubClasses().containsKey(classIndex))
return false;
and add below :
player.startAbnormalEffect(L2Character.ABNORMAL_EFFECT_HOLD_1);
player.setIsParalyzed(true);
player.sendMessage("You are paralized untill your subclass load.");
then serch for :
_log.info(getName() + " was given " + getAllSkills().length + " skills for their new sub class.");
and add below :
player.setIsParalyzed(false);
player.stopAbnormalEffect(L2Character.ABNORMAL_EFFECT_HOLD_1);
player.sendMessage("You are unparalized.");