Console error after update 1.6.0

Failed to call hook 'ccmdCategoryS' on plugin 'XSkinMenu v1.6.0' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.XSkinMenu.SetSkinItem (BasePlayer player, System.String item, System.UInt64 skin) [0x0004c] in <f2c674a1b2ef45eea62b3b8a00c81f0f>:0
  at Oxide.Plugins.XSkinMenu.ccmdCategoryS (ConsoleSystem+Arg args) [0x017c3] in <f2c674a1b2ef45eea62b3b8a00c81f0f>:0
  at Oxide.Plugins.XSkinMenu.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00a63] in <f2c674a1b2ef45eea62b3b8a00c81f0f>:0
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <d82f1fa409f84967ab685a3dbdd116ae>:0
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000de] in <d646191a355d43a6b3ab36b7ee14c740>:0
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <d646191a355d43a6b3ab36b7ee14c740>:0
Failed to call hook 'ccmdCategoryS' on plugin 'XSkinMenu v1.6.0' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.XSkinMenu.SetSkinItem (BasePlayer player, System.String item, System.UInt64 skin) [0x0004c] in <f2c674a1b2ef45eea62b3b8a00c81f0f>:0
  at Oxide.Plugins.XSkinMenu.ccmdCategoryS (ConsoleSystem+Arg args) [0x017c3] in <f2c674a1b2ef45eea62b3b8a00c81f0f>:0
  at Oxide.Plugins.XSkinMenu.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00a63] in <f2c674a1b2ef45eea62b3b8a00c81f0f>:0
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <d82f1fa409f84967ab685a3dbdd116ae>:0
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000de] in <d646191a355d43a6b3ab36b7ee14c740>:0
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <d646191a355d43a6b3ab36b7ee14c740>:0

What exactly is causing the error? What action?

There's a lot of different commands, I can't just find out what's causing the error.

Ouch... I forgot to write in the update description that this update should be install after the game update.
It has skins/items that are not yet in the current version of the game.
That's why the error occurs. 

Changed Status from Pending to Closed

Changed Fixed In to 1.6.0