Loyalty timer Crash

[Lord Neo]

The server is crashing once a hour, seems to be exactly 60-61 minutes apart from each crash. Im thinking its a Evo Dragon somewhere in the world that has been abandoned. Anyone got any ideas?

Server Crash Report
===================

RunUO Version 2.0, Build 2935.20446
Operating System: Microsoft Windows NT 5.1.2600 Service Pack 2
.NET Framework: 2.0.50727.1433
Time: 9/11/2008 8:27:01 AM
Mobiles: 24123
Items: 315411
Exception:
System.NullReferenceException: Object reference not set to an instance of an object.
   at Server.Mobiles.LoyaltyTimer.OnTick() in c:\Program Files\RUNUO\RunUO-2.0-RC1\Scripts\Engines\AI\Creature\BaseCreature.cs:line 4820
   at Server.Timer.Slice()
   at Server.Core.Main(String[] args)

Here is the Part of the code the Debug mode Report is reporting. Line 4820 is colored in blue.

				c.Say( 1043255, c.Name ); // ~1_NAME~ appears to have decided that is better off without a master!
				c.Loyalty = BaseCreature.MaxLoyalty; // Wonderfully Happy
				c.IsBonded = false;
				c.BondingBegin = DateTime.MinValue;
				c.OwnerAbandonTime = DateTime.MinValue;
				c.ControlTarget = null;
				//c.ControlOrder = OrderType.Release;
				c.AIObject.DoOrderRelease(); // this will prevent no release of creatures left alone with AI disabled (and consequent bug of Followers)

[Smjert]

It's really possible that for some reason AIObject become null.
As you said it could be Evo Dragon, so check about changes/set to AIObject.

Or better, if you have Visual Studio, you can put it in debug breakpointing AIObject here

public BaseAI AIObject{ get{ return m_AI; } }

using condition m_AI == null.
So you can watch the stack and understand what nulls it.