18:52:06 Failed to call hook 'OnDiscordGuildMemberUpdated' on plugin 'DiscordRoles v2.0.9' (ArgumentNullException: Value cannot be null.
Parameter name: key)
at System.Collections.Generic.Dictionary`2[TKey,TValue].FindEntry (TKey key) [0x00008] in <fb001e01371b4adca20013e0ac763896>:0
at System.Collections.Generic.Dictionary`2[TKey,TValue].TryGetValue (TKey key, TValue& value) [0x00000] in <fb001e01371b4adca20013e0ac763896>:0
at Oxide.Game.Rust.Libraries.Covalence.RustPlayerManager.FindPlayerById (System.String id) [0x00000] in <54e6dae8b58849bfa16cbb2bf787ce85>:0
at Oxide.Plugins.DiscordRoles.OnDiscordGuildMemberUpdated (Oxide.Ext.Discord.Entities.Guilds.GuildMember update, Oxide.Ext.Discord.Entities.Guilds.GuildMember oldMember, Oxide.Ext.Discord.Entities.Guilds.DiscordGuild guild) [0x00098] in <747cd18d2c9348f8b3cb2fc445d16f90>:0
at Oxide.Plugins.DiscordRoles.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00353] in <747cd18d2c9348f8b3cb2fc445d16f90>:0
at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <09575a60985045248bcb43b20faeeb99>:0
at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <bae5f1223fce49c493b01571c99dce02>:0
at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <bae5f1223fce49c493b01571c99dce02>:0

this ocassional error in the console, don't know what that is however it seems like it's working

Thanks for the report. This should be fixed in version 2.0.10.