Hi,
I don't know where this error came from, but it spams the console.

(08:28:57) | Creating item with less than 1 amount! (Sulfur)
(08:28:57) | Exception while calling NextTick callback (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.InstantSmelt+<OnGather>c__AnonStorey0.<>m__0 () [0x00000] in <1800dea2dd03442c889bc2483e088962>:0 
  at Oxide.Core.OxideMod.OnFrame (System.Single delta) [0x00051] in <4452f821def6406d834e4149849fe7ea>:0
(08:29:03) | Creating item with less than 1 amount! (Sulfur)
(08:29:04) | Exception while calling NextTick callback (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.InstantSmelt+<OnGather>c__AnonStorey0.<>m__0 () [0x00000] in <1800dea2dd03442c889bc2483e088962>:0 
  at Oxide.Core.OxideMod.OnFrame (System.Single delta) [0x00051] in <4452f821def6406d834e4149849fe7ea>:0​

Interesting. Thanks for report. Strange error

Failed to call hook 'OnDispenserGather' on plugin 'InstantSmelt v2.0.2' (NullReferenceException: Object reference not set to an instance of an object)
at Oxide.Plugins.InstantSmelt.OnGather (BasePlayer player, Item item, System.Boolean bonus, System.Boolean pickup) [0x00030] in :0
at Oxide.Plugins.InstantSmelt.OnDispenserGather (ResourceDispenser dispenser, BasePlayer player, Item item) [0x00000] in :0
at Oxide.Plugins.InstantSmelt.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x001c6] in :0
at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <9affce1cd15c4ec183941adef8db1722>:0
at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <4452f821def6406d834e4149849fe7ea>:0
at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <4452f821def6406d834e414​

i had error for 2 weeks
how can i solve this error?
when i used tools to resources, this error appear my server console

Edit: solved

Failed to call hook 'OnDispenserGather' on plugin 'InstantSmelt v2.0.2' (NullReferenceException: Object reference not set to an instance of an object)
at Oxide.Plugins.InstantSmelt.OnGather (BasePlayer player, Item item, System.Boolean bonus, System.Boolean pickup) [0x00030] in <248de905937b4befb7f809506190eba4>:0
at Oxide.Plugins.InstantSmelt.OnDispenserGather (ResourceDispenser dispenser, BasePlayer player, Item item) [0x00000] in <248de905937b4befb7f809506190eba4>:0
at Oxide.Plugins.InstantSmelt.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x001c6] in <248de905937b4befb7f809506190eba4>:0
at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <80b90e8213db44b29ec2d4111764172c>:0
at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <ec05e0208c9149bba43236ca58fea105>:0
at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <ec05e0208c9149bba43236ca58fea105>:0