Not an Issue Failed to run timer

How do I fix this? I don't understand what it is saying:

Code:

6:00 AM [Error] Failed to run a timer. (NullReferenceException: Object reference not set to an instance of an object)
6:00 AM [Debug]  at NLua.Method.LuaMethodWrapper..ctor (NLua.ObjectTranslator translator, System.Object target, NLua.ProxyType targetType, System.Reflection.MethodBase method) [0x00000] in <filename unknown>:0
  at NLua.MetaFunctions.GetExtensionMethod (LuaState luaState, System.Type type, System.Object obj, System.String name) [0x00000] in <filename unknown>:0
  at NLua.MetaFunctions.GetMethodInternal (LuaState luaState) [0x00000] in <filename unknown>:0
  at NLua.MetaFunctions.GetMethod (LuaState luaState) [0x00000] in <filename unknown>:0
  at (wrapper native-to-managed) NLua.MetaFunctions:GetMethod (KeraLua.LuaState)
  at (wrapper managed-to-native) KeraLua.NativeMethods:LuaNetPCall (intptr,int,int,int)
  at KeraLua.Lua.LuaNetPCall (IntPtr luaState, Int32 nArgs, Int32 nResults, Int32 errfunc) [0x00000] in <filename unknown>:0
  at NLua.LuaLib.LuaPCall (LuaState luaState, Int32 nArgs, Int32 nResults, Int32 errfunc) [0x00000] in <filename unknown>:0
  at NLua.Lua.CallFunction (System.Object function, System.Object[] args, System.Type[] returnTypes) [0x00000] in <filename unknown>:0
  at NLua.LuaFunction.Call (System.Object[] args, System.Type[] returnTypes) [0x00000] in <filename unknown>:0
  at NLua.Method.LuaDelegate.CallFunction (System.Object[] args, System.Object[] inArgs, System.Int32[] outArgs) [0x00000] in <filename unknown>:0
  at LuaGeneratedClass1.CallFunction () [0x00000] in <filename unknown>:0
  at Oxide.Core.Libraries.Timer+TimerInstance.Update () [0x00000] in <filename unknown>:0

 

Only one I can think of is the airdrop.