the repair bench does not show enchant button?

14:50 [Error] Failed to call hook 'OnLootSpawn' on plugin 'Enchanting v1.0.9' (ArgumentOutOfRangeException: Specified argument was out of the range of valid values.
Parameter name: index)
  at System.Linq.Enumerable.ElementAt[TSource] (System.Collections.Generic.IEnumerable`1[T] source, System.Int32 index) [0x0007b] in <8b0c76c7efa244bc95eeee75bf1314cd>:0 
  at Oxide.Plugins.Enchanting.GenerateRandomWeapon () [0x00017] in <a6c0a00fbcf249d3ad5a9b3582e32436>:0 
  at Oxide.Plugins.Enchanting.OnLootSpawn (LootContainer container) [0x00044] in <a6c0a00fbcf249d3ad5a9b3582e32436>:0 
  at Oxide.Plugins.Enchanting.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00ec8] in <a6c0a00fbcf249d3ad5a9b3582e32436>: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 <d59b507fd76240e5b62228d0eae39b73>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <d59b507fd76240e5b62228d0eae39b73>:0