Exception while calling NextTick callback & Failed to call hook 'OnHelicopterDropCrate'

Hi, I saw these two errors in the console, and it's related to a player who said the game kicked him out while performing the oil ring.

11/13 03:02:54 | Exception while calling NextTick callback (KeyNotFoundException: The given key 'assets/rust.ai/agents/npcplayer/humannpc/scientist/scientistnpc_oilrig.prefab' was not present in the dictionary.)
at System.Collections.Generic.Dictionary`2[TKey,TValue].get_Item (TKey key) [0x0001e] in <8ce0bd04a7a04b4b9395538239d3fdd8>:0
at Oxide.Plugins.BetterNpc.SpawnIntoContainer (ItemContainer container, System.String prefab) [0x00071] in <8300c210055b471782365a9848130470>:0
at Oxide.Plugins.BetterNpc.AddToContainerPrefab (ItemContainer container, Oxide.Plugins.BetterNpc+PrefabLootTableConfig lootTable) [0x00086] in <8300c210055b471782365a9848130470>:0
at Oxide.Plugins.BetterNpc+ControllerSpawnPoint+<>c__DisplayClass16_0.<DieNpc>b__1 () [0x0009c] in <8300c210055b471782365a9848130470>:0
at Oxide.Core.OxideMod.OnFrame (System.Single delta) [0x00051] in <112d89ea5d3348c8b949af0ab1a866d2>:0

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11/13 02:37:44 | Failed to call hook 'OnHelicopterDropCrate' on plugin 'BetterNpc v1.3.3' (KeyNotFoundException: The given key 'CH47' was not present in the dictionary.)
at System.Collections.Generic.Dictionary`2[TKey,TValue].get_Item (TKey key) [0x0001e] in <8ce0bd04a7a04b4b9395538239d3fdd8>:0
at Oxide.Plugins.BetterNpc.OnHelicopterDropCrate (CH47HelicopterAIController ai) [0x00000] in <8300c210055b471782365a9848130470>:0
at Oxide.Plugins.BetterNpc.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x007f6] in <8300c210055b471782365a9848130470>:0
at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <42f9bedc659b4f4786eb778d3cd58968>:0
at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000de] in <112d89ea5d3348c8b949af0ab1a866d2>:0
at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <112d89ea5d3348c8b949af0ab1a866d2>:0