[Error] Failed to call hook 'CanStackItem' on plugin 'StackSizeController v3.3.0' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.StackSizeController.CanStackItem (Item item, Item targetItem) [0x0021f] in <11a0fcab41574a75b0cb6e23607cb3c1>:0 
  at Oxide.Plugins.StackSizeController.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00e7b] in <11a0fcab41574a75b0cb6e23607cb3c1>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <31122a27a2414cd799150f8677cf39d4>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <c2afd8354b8b4f3ca451cf5a1aa111c3>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <c2afd8354b8b4f3ca451cf5a1aa111c3>:0 

Calling hook CanStackItem resulted in a conflict between the following plugins: BuriedTreasure - False (Boolean), StackSizeController (True (Boolean))

I'm getting that after updating to latest version of StackSize

Oh right, we have Buried Treasure, too. But I have not seen any warning or error due to a conflict

Calling hook CanStackItem resulted in a conflict between the following plugins: JPipes - False (Boolean), StackSizeController (True (Boolean))

There's another one.

All should be resolved in latest release, let me know if any new ones pop up.