UserPersistance.AddLifeStory NRE

Code:

NullReferenceException: Object reference not set to an instance of an object
UserPersistance.AddLifeStory (UInt64 playerID, ProtoBuf.PlayerLifeStory lifeStory)
BasePlayer.LifeStoryEnd ()
BasePlayer.OnKilled (.HitInfo info)
BaseCombatEntity.Die (.HitInfo info)
BasePlayer.Die (.HitInfo info)
BaseCombatEntity.Hurt (.HitInfo info, Boolean useProtection)
BasePlayer.Hurt (.HitInfo info, Boolean useProtection)
BaseCombatEntity.OnAttacked (.HitInfo info)
BasePlayer.OnAttacked (.HitInfo info)
BasePlayer.OnProjectileAttack (RPCMessage msg)
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters)
BaseEntity+<FindRPCMessage>c__AnonStorey1F.<>m__15 (RPCMessage rpcMsg)
BaseEntity.SV_RPCMessage (UInt32 nameID, Network.Message message)
UnityEngine.Debug:LogException(Exception)
BaseEntity:SV_RPCMessage(UInt32, Message)
ServerMgr:OnRPCMessage(Message)
ServerMgr:OnNetworkMessage(Message)
Network.Implementation.Raknet.Server:ConnectedPacket(RaknetConnection)
Network.Implementation.Raknet.Server:Cycle()
ServerMgr:Update()

Should I ignore it?
Should I ignore it? or I have to wait until next update? or what should I do?