System.NullReferenceException: Object reference not set to an instance of an obj
ect.
at Server.Items.CannonComponent.Damage(Mobile from, Int32 damage)
at Server.Items.CannonComponent.Explode(Mobile from, Point3D loc, Map map)
at Server.Items.CannonComponent.CheckFiringAngle(Point3D p, Mobile from)
at Server.Mobiles.BaseCannonGuard.FireCannon(Mobile target)
at Server.Mobiles.BaseCannonGuard.OnCombatantChange()
at Server.Mobile.set_Combatant(Mobile value)
at Server.Mobiles.ArcherAI.DoActionGuard()
at Server.Mobiles.BaseAI.Think()
at Server.Mobiles.AITimer.OnTick()
at Server.Timer.Slice()
at Server.Core.Main(String[] args)

no, I believe that is from some other custom cannon system.