Failed to call hook 'OnServerInitialized' on plugin 'DiscordTeam v1.1.1' (NullReferenceException: Object reference not set to an instance of an object.)
  at Oxide.Plugins.DiscordTeam.initializeTeam () [0x00036] in <546ad981f0e1410bb9111ce0d05e5abf>:0

  at Oxide.Plugins.DiscordTeam.StartDiscordTeam () [0x000be] in <546ad981f0e1410bb9111ce0d05e5abf>:0

  at Oxide.Plugins.DiscordTeam.OnServerInitialized () [0x00000] in <546ad981f0e1410bb9111ce0d05e5abf>:0

  at Oxide.Plugins.DiscordTeam.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00147] in <546ad981f0e1410bb9111ce0d05e5abf>: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

Failed to call hook 'OnUserConnected' on plugin 'DiscordTeam v1.1.1' (NullReferenceException: Object reference not set to an instance of an object.)
  at Oxide.Plugins.DiscordTeam.OnUserConnected (Oxide.Core.Libraries.Covalence.IPlayer player) [0x00046] in <546ad981f0e1410bb9111ce0d05e5abf>:0

  at Oxide.Plugins.DiscordTeam.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x0016a] in <546ad981f0e1410bb9111ce0d05e5abf>: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

Weird, what plugin are you using for registering players ? Discord Connect or Discord Auth ?

DiscordAuth.

Problem solved, it fully work with DiscordAuth now ! Thanks for your report !