Help me im Stupid

First of all Nice Plugin but im to stupid.

How can i change the sikins' (my self-created skins?)

And 2nd when the node is melted, this message comes up

(22:53:43) | Failed to call hook 'OnDispenserBonus' on plugin 'EpicLoot v1.1.1' (NullReferenceException: Object reference not set to an instance of an object)
  at BasePlayer.GiveItem (Item item, BaseEntity+GiveItemReason reason) [0x0004c] in <bd55da73323340f6bdbb8f35571e6ed4>:0 
  at Oxide.Plugins.EpicLoot.HandleDispenser (ResourceDispenser dispenser, BasePlayer player, Item item, System.Boolean bonus) [0x0065c] in <4368744e2c614e51804be14740869e4d>:0 
  at Oxide.Plugins.EpicLoot.OnDispenserBonus (ResourceDispenser dispenser, BasePlayer player, Item item) [0x00000] in <4368744e2c614e51804be14740869e4d>:0 
  at Oxide.Plugins.EpicLoot.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x02bcd] in <4368744e2c614e51804be14740869e4d>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <b6af59acae274e5a94fb209dfc179b8f>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <bae5f1223fce49c493b01571c99dce02>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <bae5f1223fce49c493b01571c99dce02>:0
(22:54:50) | [Economics] Saving balances for players...
(22:54:50) | Saved 154,970 ents, cache(0.07), write(0.02), disk(0.02).
(22:54:50) | Saving complete
(22:54:51) | [SmoothRestarter] Fetching latest Oxide.Rust version...
(22:54:51) | [SmoothRestarter] Current Oxide.Rust version is up-to-date, scheduling check after 600 seconds...

Is it randomly happening or is it happening constantly?

Would you know what action is being done to cause it?

Check the config for where to edit skins. Should be near the bottom.

Changed Status from Pending to No Response