Hello,
I've been trying to install your plugin on my server for a day. Previously I never had any problems with your plugin.
But now nothing helps so maybe it's coming from the "permission" section in the json or maybe I'm doing the wrong thing.
But in any case here is what the console tells me when I put:
{
      "Item Shortname": "box.wooden.large",
"Permission": "",
      "Skins": [
        0,
        1886917011,
        2000024196,
        1922735686,
        809371945,
        1226375015,
        1594986652,
        922352837,
        1368152691,
        1959866973,
        1959864962,
        1959859647,
        1959838110,
        1959821476
      ]
    }
and here is the console response:
Failed to call hook 'OnItemAddedToContainer' on plugin 'Skins v2.2.2' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.Skins+ContainerController.DrawUI (System.Int32 page) [0x0003f] in <d4ae764dcb3e4a9dab9794a2726ea594>:0
  at Oxide.Plugins.Skins+ContainerController.UpdateContent (System.Int32 page) [0x00205] in <d4ae764dcb3e4a9dab9794a2726ea594>:0
  at Oxide.Plugins.Skins.OnItemAddedToContainer (ItemContainer itemContainer, Item item) [0x000a2] in <d4ae764dcb3e4a9dab9794a2726ea594>:0
  at Oxide.Plugins.Skins.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x002f3] in <d4ae764dcb3e4a9dab9794a2726ea594>:0
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <60c318df79ed41688ea59335e48d61ad>:0
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <50629aa0e75d4126b345d8d9d64da28d>:0
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <50629aa0e75d4126b345d8d9d64da28d>:0
Unloaded plugin Skins v2.2.2 by misticos

does it still show that after reloading the plugin?