07:01 [Error] Failed to call hook 'OnDiscordClientCreated' on plugin 'Rustcord v3.3.2' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.Rustcord.SubscribeHooks () [0x00511] in <f8152a19d881469aa6f9d381b7ccf1a9>:0 
  at Oxide.Plugins.Rustcord.OnDiscordClientCreated () [0x0010e] in <f8152a19d881469aa6f9d381b7ccf1a9>:0 
  at Oxide.Plugins.Rustcord.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00a1c] in <f8152a19d881469aa6f9d381b7ccf1a9>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <23ba99f131254889867c71f0bd137b1d>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <157a94ee66ab4a7991faecd1eb84be3b>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <157a94ee66ab4a7991faecd1eb84be3b>:0 
07:01 [Info] Loaded plugin Rustcord v3.3.2 by Kirollos & OuTSMoKE
07:01 [Info] Loaded plugin Server Info v0.5.8 by FastBurst
07:01 [Info] [Stack Size Controller] Acquiring vanilla defaults file from official GitHub repo and overwriting; https://raw.githubusercontent.com/AnExiledDev/StackSizeController/master/vanilla-defaults.json
07:01 [Info] Loaded plugin Stack Size Controller v4.1.1 by AnExiledDev
07:01 [Info] Loaded plugin Tea Modifiers v2.0.0 by MJSU
07:01 [Info] Loaded plugin Vanish v1.8.0 by Whispers88
07:01 [Info] Loaded plugin ZLevels Remastered v3.1.7 by nivex
7:01 AM [Info] [Discord Extension] [Info]: Discord socket opened!
7:01 AM [Info] [Discord Extension] [Info]: Your bot was found in 1 Guilds!
07:01 [Error] Failed to call hook 'OnDiscordGatewayReady' on plugin 'Rustcord v3.3.2' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.Rustcord.SubscribeHooks () [0x00511] in <f8152a19d881469aa6f9d381b7ccf1a9>:0 
  at Oxide.Plugins.Rustcord.OnDiscordGatewayReady (Oxide.Ext.Discord.Entities.Gatway.Events.GatewayReadyEvent rdy) [0x00011] in <f8152a19d881469aa6f9d381b7ccf1a9>:0 
  at Oxide.Plugins.Rustcord.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00a58] in <f8152a19d881469aa6f9d381b7ccf1a9>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <23ba99f131254889867c71f0bd137b1d>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <157a94ee66ab4a7991faecd1eb84be3b>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <157a94ee66ab4a7991faecd1eb84be3b>:0 

Out of curiousity, are you noticing increased, heavy lag on the server after seeing the message?  I think my RustCord is having an issue as well, unable to pinpoint it though, and is causing severe lag.  But I cannot say the lag is because of RustCord.