Server Crash Error

[pavone1987]

Hello there, i'm trying to figure out this problem:

Server Crash Report
===================
 
RunUO Version 2.0, Build 4628.34607
Operating System: Microsoft Windows NT 6.1.7601 Service Pack 1
.NET Framework: 2.0.50727.5472
Time: 25/01/2014 00:28:15
Mobiles: 6237
Items: 52648
Exception:
System.ArgumentOutOfRangeException: Index non compreso nell'intervallo. Richiesto valore non negativo e minore della dimensione dell'insieme.
Nome parametro: index
   in System.ThrowHelper.ThrowArgumentOutOfRangeException()
   in System.Collections.Generic.List`1.RemoveAt(Int32 index)
   in Joeku.ToolbarEdit.GetEntry(Int32 entryID, ToolbarEdit gump)
   in Joeku.ToolbarEdit.AnalyzeEntries(Int32 i)
   in Joeku.ToolbarEdit.OnResponse(NetState sender, RelayInfo info)
   in Server.Network.PacketHandlers.DisplayGumpResponse(NetState state, PacketReader pvSrc)
   in Server.Network.MessagePump.HandleReceive(NetState ns)
   in Server.Network.MessagePump.Slice()
   in Server.Core.Main(String[] args)

Can u plz explain me what i have to search for?