Failed to call hook 'OnDispenserBonusReceived'

Hi! There are a lot of errors when starting an Gold Rush event.

[Oxide] 09:52 [Error] Failed to call hook 'OnDispenserBonusReceived' on plugin 'MultiEventsGoldRush v1.0.0' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.MultiEventsGoldRush+Configuration+<>c__DisplayClass5_0.<GetPermissionMultiplier>b__0 (System.Collections.Generic.KeyValuePair`2[TKey,TValue] check) [0x00012] in <ad747f7854344f23a901d109ccd24a01>:0
  at System.Linq.Enumerable+WhereEnumerableIterator`1[TSource].MoveNext () [0x00037] in <a314714511a14f84b853c03efd8682b8>:0
  at System.Linq.Enumerable.Aggregate[TSource,TAccumulate] (System.Collections.Generic.IEnumerable`1[T] source, TAccumulate seed, System.Func`3[T1,T2,TResult] func) [0x00037] in <a314714511a14f84b853c03efd8682b8>:0
  at Oxide.Plugins.MultiEventsGoldRush+Configuration.GetPermissionMultiplier (BasePlayer player) [0x00024] in <ad747f7854344f23a901d109ccd24a01>:0
  at Oxide.Plugins.MultiEventsGoldRush.RollItems (BasePlayer player, System.Collections.Generic.List`1[T] items) [0x00011] in <ad747f7854344f23a901d109ccd24a01>:0
  at Oxide.Plugins.MultiEventsGoldRush.OnDispenserBonusReceived (ResourceDispenser dispenser, BasePlayer player, Item item) [0x00048] in <ad747f7854344f23a901d109ccd24a01>:0
  at Oxide.Plugins.MultiEventsGoldRush.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x000b8] in <ad747f7854344f23a901d109ccd24a01>:0
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <42f9bedc659b4f4786eb778d3cd58968>:0
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000de] in <112d89ea5d3348c8b949af0ab1a866d2>:0
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <112d89ea5d3348c8b949af0ab1a866d2>:0

Hello! Please, send me your config