Latest Rust and Oxide versions. Getting tons of errors on server load:

Failed to call hook 'OnMaxStackable' on plugin 'StackSizeController v4.1.1' (NullReferenceException: Object reference not set to an instance of an object)
at Oxide.Plugins.StackSizeController.GetVanillaStackSize (ItemDefinition itemDefinition) [0x00000] in <2b88e91047a240eb92996392334030ca>:0
at Oxide.Plugins.StackSizeController.GetStackSize (ItemDefinition itemDefinition) [0x001b2] in <2b88e91047a240eb92996392334030ca>:0
at Oxide.Plugins.StackSizeController.OnMaxStackable (Item item) [0x00000] in <2b88e91047a240eb92996392334030ca>:0
at Oxide.Plugins.StackSizeController.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00efc] in <2b88e91047a240eb92996392334030ca>: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 <12678b905a6d43c3a9cc366104306651>:0
at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <12678b905a6d43c3a9cc366104306651>:0​

Then it's most likely a one-off error and can be ignored.