Spawn Errors

Getting this semi-frequently in console:

Failed to call hook 'SpawnNpc' on plugin 'NpcSpawn v2.8.4' (NullReferenceException: Object reference not set to an instance of an object) at Oxide.Plugins.NpcSpawn+CustomScientistNpc.UpdateInventory () [0x00116] in :0 at Oxide.Plugins.NpcSpawn+CustomScientistNpc.ServerInit () [0x00164] in :0 at BaseNetworkable.Spawn () [0x0004f] in :0 at BaseEntity.Spawn () [0x00000] in :0 at Oxide.Plugins.NpcSpawn.CreateCustomNpc (UnityEngine.Vector3 position, Oxide.Plugins.NpcSpawn+NpcConfig config) [0x0007b] in :0 at Oxide.Plugins.NpcSpawn.SpawnNpc (UnityEngine.Vector3 position, Newtonsoft.Json.Linq.JObject configJson) [0x00008] in :0 at Oxide.Plugins.NpcSpawn.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x000b0] in :0 at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in :0 at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000de] in :0 at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in :0