Many errors when the players use the BackPack :

Failed to call hook 'OnBackpackOpened' on plugin 'SortButton v0.0.7' (KeyNotFoundException: The given key was not present in the dictionary.)
at System.Collections.Generic.Dictionary`2[TKey,TValue].get_Item (TKey key) [0x0001e] in <437ba245d8404784b9fbab9b439ac908>:0
at Oxide.Plugins.SortButton.OnBackpackOpened (BasePlayer player, System.UInt64 backpackOwnerID, ItemContainer backpackContainer) [0x00029] in <3b5bcc9a425c4072b236b83668dc8043>:0
at Oxide.Plugins.SortButton.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00486] in <3b5bcc9a425c4072b236b83668dc8043>:0
at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <d09a1f46ca2f4432811bcfe45ad13c7b>:0
at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <cf88a28c7fb44d36890d85a78331cc9d>:0
at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <cf88a28c7fb44d36890d85a78331cc9d>:0

Please, make sure you have deleted old configuration file before updating to this version.
Delete (rename) it, reload the plugin and tell me if it helps.

Ok I try this now. And come back to say what happens or not.

Merged post

In the old conf this part arent present :

  "backpack": {
    "OrderButtonHeight": 0.028,
    "OrderButtonWidth": 0.01,
    "OrderButtonX": 0.8755,
    "OrderButtonY": 0.758,
    "SortButtonHeight": 0.028,
    "SortButtonWidth": 0.06,
    "SortButtonX": 0.8865,
    "SortButtonY": 0.758
  },

Certainly the problem.
For the moment no errors on my logs !
Thanks !!!