My humanNPC data file keeps resetting itself to blank and losing all of my NPC data. My NPCs start firing slowly after about 15 minutes.  NPC_Reset comes back with "No NPCs found" even though  the NPC is standing there shooting at me. 

System.NullReferenceException: Object reference not set to an instance of an object
  at BaseAIBrain`1[T].Think (System.Single delta) [0x00095] in <d6b7625eccf442ceba599ededcf17416>:0 
  at BaseAIBrain`1[T].DoThink () [0x0000d] in <d6b7625eccf442ceba599ededcf17416>:0 
  at HumanNPC.ServerThink (System.Single delta) [0x00014] in <d6b7625eccf442ceba599ededcf17416>:0 
  at NPCPlayer.ServerThink_Internal () [0x0000d] in <d6b7625eccf442ceba599ededcf17416>:0 
  at HumanNPC.TryThink () [0x00000] in <d6b7625eccf442ceba599ededcf17416>:0 
  at AIThinkManager.DoProcessing (ListHashSet`1[T] process, System.Single budgetSeconds, System.Int32& last) [0x00014] in <d6b7625eccf442ceba599ededcf17416>:0