All events error out (second time I'm typing this post that I spent 20 minutes in details at first, but this site timed out or denied my post. So I'm going to be vauge on this but it should be straight forward.) If I had to take a wild guess I need to make web hooks for these, but I hope that's not the case since the plugin and extension don't state this. I'm hoping I'm doing something stupid.
On server load:
21:11 [Info] Loaded extension Discord v1.0.0 by PsychoTea & DylanSMR
21:11 [Info] Loaded plugin Rustcord v1.1.1 by Kirollos & OuTSMoKE
9:11 PM [Warning] [Discord Ext] An error has occured: Response: An exception has occurred during the OnClose event.

Player chat:

21:03 [Error] Failed to call hook 'OnPlayerChat' on plugin 'Rustcord v1.1.1' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Ext.Discord.DiscordObjects.Channel.GetChannel (Oxide.Ext.Discord.DiscordClient client, System.String channelID, System.Action`1[T] callback) [0x00001] in <a5b2f558069e40f7b83de551a4df08a5>:0

  at Oxide.Plugins.Rustcord+<OnPlayerChat>c__AnonStorey0.<>m__0 (Oxide.Plugins.Rustcord+Settings+Channel ch) [0x00011] in <f7011db2e2da4e69ab1bfb27b51699d4>:0

  at System.Collections.Generic.List`1[T].ForEach (System.Action`1[T] action) [0x00024] in <ac823e2bb42b41bda67924a45a0173c3>:0

  at Oxide.Plugins.Rustcord.OnPlayerChat (ConsoleSystem+Arg arg) [0x0015e] in <f7011db2e2da4e69ab1bfb27b51699d4>:0

  at Oxide.Plugins.Rustcord.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x001cd] in <f7011db2e2da4e69ab1bfb27b51699d4>:0

  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <9affce1cd15c4ec183941adef8db1722>:0

  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <4452f821def6406d834e4149849fe7ea>:0

  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <4452f821def6406d834e4149849fe7ea>:0

Player disconnect:

21:03 [Error] Failed to call hook 'OnPlayerDisconnected' on plugin 'Rustcord v1.1.1' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Ext.Discord.DiscordObjects.Channel.GetChannel (Oxide.Ext.Discord.DiscordClient client, System.String channelID, System.Action`1[T] callback) [0x00001] in <a5b2f558069e40f7b83de551a4df08a5>:0

  at Oxide.Plugins.Rustcord+<OnPlayerDisconnected>c__AnonStorey2.<>m__0 (Oxide.Plugins.Rustcord+Settings+Channel ch) [0x00011] in <f7011db2e2da4e69ab1bfb27b51699d4>:0

  at System.Collections.Generic.List`1[T].ForEach (System.Action`1[T] action) [0x00024] in <ac823e2bb42b41bda67924a45a0173c3>:0

  at Oxide.Plugins.Rustcord.OnPlayerDisconnected (BasePlayer player, System.String reason) [0x0004d] in <f7011db2e2da4e69ab1bfb27b51699d4>:0

  at Oxide.Plugins.Rustcord.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00226] in <f7011db2e2da4e69ab1bfb27b51699d4>:0

  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <9affce1cd15c4ec183941adef8db1722>:0

  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <4452f821def6406d834e4149849fe7ea>:0

  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <4452f821def6406d834e4149849fe7ea>:0

Hi, I am not the plugin dev however I do have the plugin working rather well on my server. All I am going to ask you is to make sure you are running the latest version of uMod and also that I had a friend who for some reason had a corrupt version of RustCord.cs that was also having a compiling issue so if you are sure you are running the latest version of uMod and still having issues, I will ask that you maybe post your config(with your api key and discord channel ID's removed) for us to look into for you. I would also ask you to maybe attach the RustCord.cs file you are using so I can try see if yours is different from mine. Also please make sure you are using BetterChat with your server else your messages will not go through to the Discord server. To my knowledge the chat only works with BetterChat

I too also have this issue.  It's only with certain commands though from what I can tell

I receve the same problems at times but get not problems after restart.

Extension update fixed these issues.