Using Command "stacksizecontroller.itemsearch pic" causes error

If i use this command "stacksizecontroller.itemsearch pic" a weird error occurs:

Failed to call hook 'ItemSearchCommand' on plugin 'StackSizeController v4.1.3' (KeyNotFoundException: The given key 'concretepickaxe' was not present in the dictionary.)
  at System.Collections.Generic.Dictionary`2[TKey,TValue].get_Item (TKey key) [0x0001e] in <f98723dd4586469db5213ec59da723ca>:0 
  at Oxide.Plugins.StackSizeController.ItemSearchCommand (Oxide.Core.Libraries.Covalence.IPlayer player, System.String command, System.String[] args) [0x000d9] in <714e1121b406418e9322c7f9ab64beb6>:0 
  at Oxide.Plugins.StackSizeController.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00074] in <714e1121b406418e9322c7f9ab64beb6>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <795304323ac74a298b8ed190a1dfa739>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000de] in <beb2b64691c64e2b95b99491bd85442c>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <beb2b64691c64e2b95b99491bd85442c>:0 

The key concretepickaxe is contained in the config file 🤷‍♂️

Same here. all the console commands given in the docs dont work. The military flamethrower and tin can alarm are missing from the config and if you add them they still wont stack, used to get an error for "hard coded" items that you could not stack but no error pops up for these two.

Same problem here

I also encountered this problem. Is there a solution?