Error Failed to call hook 'ConfirmPurchaseIndustrial'

[Oxide] 18:01 [Error] Failed to call hook 'ConfirmPurchaseIndustrial' on plugin 'IndustrialRecycler v1.8.94' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.IndustrialRecycler+<>c__DisplayClass124_0.<RemoveItems>b__0 (Item item) [0x00000] in <f2ef0ab7a7034a7bbdec48bdeb7ce8d9>:0
  at System.Linq.Enumerable+WhereListIterator`1[TSource].MoveNext () [0x00037] in <80564d689e48448fa2a7101993ee7201>:0
  at Oxide.Plugins.IndustrialRecycler.RemoveItems (System.Collections.Generic.List`1[T] allItems, BasePlayer player, System.Collections.Generic.Dictionary`2[TKey,TValue] requiredItemMap) [0x000c2] in <f2ef0ab7a7034a7bbdec48bdeb7ce8d9>:0
  at Oxide.Plugins.IndustrialRecycler.CheckAndRemoveBuyItems (BasePlayer player, System.Collections.Generic.List`1[T] requiredItems) [0x00066] in <f2ef0ab7a7034a7bbdec48bdeb7ce8d9>:0
  at Oxide.Plugins.IndustrialRecycler.ConfirmPurchaseIndustrial (ConsoleSystem+Arg arg) [0x00046] in <f2ef0ab7a7034a7bbdec48bdeb7ce8d9>:0
  at Oxide.Plugins.IndustrialRecycler.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x014e8] in <f2ef0ab7a7034a7bbdec48bdeb7ce8d9>: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 <15f61ddda771464d8246ebdce8ff4811>:0
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <15f61ddda771464d8246ebdce8ff4811>:0