[Error] Failed to call hook 'OnPlayerChat' on plugin 'Rustcord v2.1.0' (ArgumentNullException: Value cannot be null.
Parameter name: source)
  at System.Linq.Enumerable.TryGetFirst[TSource] (System.Collections.Generic.IEnumerable`1[T] source, System.Func`2[T,TResult] predicate, System.Boolean& found) [0x0000d] in <351e49e2a5bf4fd6beabb458ce2255f3>:0
  at System.Linq.Enumerable.FirstOrDefault[TSource] (System.Collections.Generic.IEnumerable`1[T] source, System.Func`2[T,TResult] predicate) [0x00000] in <351e49e2a5bf4fd6beabb458ce2255f3>:0
  at Oxide.Plugins.Rustcord+<GetChannel>c__AnonStorey8.<>m__0 (Oxide.Ext.Discord.DiscordObjects.Guild x) [0x00006] in <ac28f9e0c7a0467d87bbe39a423fbe45>:0
  at System.Linq.Enumerable.TryGetFirst[TSource] (System.Collections.Generic.IEnumerable`1[T] source, System.Func`2[T,TResult] predicate, System.Boolean& found) [0x0003f] in <351e49e2a5bf4fd6beabb458ce2255f3>:0
  at System.Linq.Enumerable.FirstOrDefault[TSource] (System.Collections.Generic.IEnumerable`1[T] source, System.Func`2[T,TResult] predicate) [0x00000] in <351e49e2a5bf4fd6beabb458ce2255f3>:0
  at Oxide.Plugins.Rustcord.GetChannel (Oxide.Ext.Discord.DiscordClient c, System.String chan_id, System.Action`1[T] cb, System.String guildid) [0x0001a] in <ac28f9e0c7a0467d87bbe39a423fbe45>:0
  at Oxide.Plugins.Rustcord.OnPlayerChat (BasePlayer player, System.String message, ConVar.Chat+ChatChannel channel) [0x001ec] in <ac28f9e0c7a0467d87bbe39a423fbe45>:0
  at Oxide.Plugins.Rustcord.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x003b2] in <ac28f9e0c7a0467d87bbe39a423fbe45>:0
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <008b12f41ec4452da1a5497eeb849299>:0
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <ac41dd3599754d448b8c218b34645820>:0
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <ac41dd3599754d448b8c218b34645820>:0

Out of date extension, was fixed in Extension 1.0.6