Follwed the instructions for 2.0  when the game starts this pops in console and no one can make a guess also on the main plugin page chat commands you have

• /color start(Manually start a round of Math with permission assigned)

 | Failed to call hook 'CmdColorMain' on plugin 'TellMeC v2.0.0' (NullReferenceException: Object reference not set to an instance of an object)
  at BasePlayer.GiveItem (Item item, BaseEntity+GiveItemReason reason) [0x0004c] in <2406f895d44c473ebb02adb659bcf57d>:0 
  at Oxide.Plugins.TellMeC.GivePlayerGift (BasePlayer player, System.String gift, System.UInt64 skin, System.Int32 quantity) [0x00063] in <fae5f32996c64c30b3948cc3f9570018>:0 
  at Oxide.Plugins.TellMeC.HandlePlayerGuess (BasePlayer player, System.String guess) [0x0018b] in <fae5f32996c64c30b3948cc3f9570018>:0 
  at Oxide.Plugins.TellMeC.CmdColorMain (BasePlayer player, System.String command, System.String[] args) [0x00029] in <fae5f32996c64c30b3948cc3f9570018>:0 
  at Oxide.Plugins.TellMeC.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00220] in <fae5f32996c64c30b3948cc3f9570018>: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 <d59b507fd76240e5b62228d0eae39b73>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <d59b507fd76240e5b62228d0eae39b73>:0

OK so I guess you cant have a min quanity of 0 

that is correct reminds me to put in a check if its 0.

You can add remove items if you dont want it to be listed

Yeah I normally use 0 so there is a chance of getting it so yeah I did exactly that and just removed the ones I didnt want instead thank you