OpenNos NoFunction items crash

/*
* This file is part of the OpenNos Emulator Project. See AUTHORS file for Copyright information
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/

using OpenNos.Core;
using OpenNos.Data;
using OpenNos.GameObject.Networking;

namespace OpenNos.GameObject
{
public class NoFunctionItem : Item
{
#region Instantiation

public NoFunctionItem(ItemDTO item) : base(item)
{
}

#endregion

#region Methods

public override void Use(ClientSession session, ref ItemInstance inv, byte Option = 0, string[] packetsplit = null)
{
switch (Effect)
{
case 10:
{
switch (EffectValue)
{
case 1:
if (session.Character.Inventory.CountItem(1036) < 1 || session.Character.Inventory.CountItem(1013) < 1)
{
return;
}
session.Character.Inventory.RemoveItemAmount(1036) ;
session.Character.Inventory.RemoveItemAmount(1013) ;
if (ServerManager.RandomNumber() < 25)
{
switch (ServerManager.RandomNumber(0, 2))
{
case 0:
session.Character.GiftAdd(1015, 1);
break;
case 1:
session.Character.GiftAdd(1016, 1);
break;
}
}
break;
case 2:
if (session.Character.Inventory.CountItem(1038) < 1 || session.Character.Inventory.CountItem(1013) < 1)
{
return;
}
session.Character.Inventory.RemoveItemAmount(1038) ;
session.Character.Inventory.RemoveItemAmount(1013) ;
if (ServerManager.RandomNumber() < 25)
{
switch (ServerManager.RandomNumber(0, 4))
{
case 0:
session.Character.GiftAdd(1031, 1);
break;
case 1:
session.Character.GiftAdd(1032, 1);
break;
case 2:
session.Character.GiftAdd(1033, 1);
break;
case 3:
session.Character.GiftAdd(1034, 1);
break;
}
}
break;
case 3:
if (session.Character.Inventory.CountItem(1037) < 1 || session.Character.Inventory.CountItem(1013) < 1)
{
return;
}
session.Character.Inventory.RemoveItemAmount(1037) ;
session.Character.Inventory.RemoveItemAmount(1013) ;
if (ServerManager.RandomNumber() < 25)
{
switch (ServerManager.RandomNumber(0, 17))
{
case 0:
case 1:
case 2:
case 3:
case 4:
session.Character.GiftAdd(1017, 1);
break;
case 5:
case 6:
case 7:
case 8:
session.Character.GiftAdd(1018, 1);
break;
case 9:
case 10:
case 11:
session.Character.GiftAdd(1019, 1);
break;
case 12:
case 13:
session.Character.GiftAdd(1020, 1);
break;
case 14:
session.Character.GiftAdd(1021, 1);
break;
case 15:
session.Character.GiftAdd(1022, 1);
break;
case 16:
session.Character.GiftAdd(1023, 1);
break;
}
}
break;
}

session.Character.GiftAdd(1014, (byte)ServerManager.RandomNumber(5, 11));
}
break;
default:
Logger.Warn(string.Format(Language.Instance.GetMes sageFromKey("NO_HANDLER_ITEM"), GetType(), VNum, Effect, EffectValue));
break;
}
}

#endregion
}
}