Failed to call hook 'ChatCMD' on plugin 'DiscordRewards v1.1.6' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.DiscordRewards.ChatCMD (Oxide.Core.Libraries.Covalence.IPlayer player, System.String command, System.String[] args) [0x00055] in <dca9a02513e143ac99405995bd4af4e1>:0 
  at Oxide.Plugins.DiscordRewards.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00214] in <dca9a02513e143ac99405995bd4af4e1>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <41771c7bc8d246d0b0a34c2f0d27f2cb>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <b0a93b504f034a0db8b1c3d2503c0987>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <b0a93b504f034a0db8b1c3d2503c0987>:0

Can't make it work? 

Failed to call hook 'ChatCMD' on plugin 'DiscordRewards v1.1.6' (NullReferenceException: Object reference not set to an instance of an object) at Oxide.Plugins.DiscordRewards.m__1 (System.String s) [0x00000] in :0 at System.Linq.Enumerable+SelectIPartitionIterator`2[TSource,TResult].PreallocatingToArray (System.Int32 count) [0x0001e] in :0 at System.Linq.Enumerable+SelectIPartitionIterator`2[TSource,TResult].ToArray () [0x00023] in :0 at System.Linq.Enumerable.ToArray[TSource] (System.Collections.Generic.IEnumerable`1[T] source) [0x0001f] in :0 at Oxide.Plugins.DiscordRewards.RandomString (System.Int32 length) [0x00022] in :0 at Oxide.Plugins.DiscordRewards.ChatCMD (Oxide.Core.Libraries.Covalence.IPlayer player, System.String command, System.String[] args) [0x0010e] in :0 at Oxide.Plugins.DiscordRewards.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00214] in :0 at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <33f7c42a56934dae8ec04b11017dce31>:0 at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in :0 at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in :0​

Merged post

Solved myself thanks for merge.

Any ideas? Happend since latest update

Failed to call hook 'ChatCMD' on plugin 'DiscordRewards v1.3.1' (NullReferenceException: Object reference not set to an instance of an object) at Oxide.Plugins.DiscordRewards.m__1 (System.String s) [0x00000] in <7feb5fc4b8bd41ddae40b497ef8bafea>:0 at System.Linq.Enumerable+SelectIPartitionIterator`2[TSource,TResult].PreallocatingToArray (System.Int32 count) [0x0001e] in <351e49e2a5bf4fd6beabb458ce2255f3>:0 at System.Linq.Enumerable+SelectIPartitionIterator`2[TSource,TResult].ToArray () [0x00023] in <351e49e2a5bf4fd6beabb458ce2255f3>:0 at System.Linq.Enumerable.ToArray[TSource] (System.Collections.Generic.IEnumerable`1[T] source) [0x0001f] in <351e49e2a5bf4fd6beabb458ce2255f3>:0 at Oxide.Plugins.DiscordRewards.RandomString (System.Int32 length) [0x00022] in <7feb5fc4b8bd41ddae40b497ef8bafea>:0 at Oxide.Plugins.DiscordRewards.ChatCMD (Oxide.Core.Libraries.Covalence.IPlayer player) [0x0010e] in <7feb5fc4b8bd41ddae40b497ef8bafea>:0 at Oxide.Plugins.DiscordRewards.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x0028f] in <7feb5fc4b8bd41ddae40b497ef8bafea>:0 at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <70dc8de1abd4423db5f501c6845edf22>:0 at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in :0 at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in :0​

Merged post

Fixed, forgot to delete config.