NullReferenceException at OnPlayerDisconected

Hello! Today turned player - said friend can not connect. Play with 1 IP. Clarified - on other servers everything seemed to be normal.
I found this error in the console.
I do not know, for me it is not critical - the situation is not standard, so that they play with 1 IP. But still, I decided to write.

(21:20:45) | Failed to call hook 'OnPlayerDisconnected' on plugin 'Recycle v2.1.9' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.Recycle.OnPlayerDisconnected (BasePlayer player) [0x0000c] in <5838072522f04212b3ff4af23d6860c9>:0 
  at Oxide.Plugins.Recycle.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x0045e] in <5838072522f04212b3ff4af23d6860c9>: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
(21:20:45) | [Welcomer] ✘ Eygeny покинул сервер (Kicked: Duplicate IP. Обратитесь к Администратору.)
Wulf answered that it is not from RECYCLE
sorry
In response to ZLOGRA ():
Hello! Today turned player - said friend can not connect. Play with 1 IP. Clarified - on other serve...
According to the log file the player was kicked because of
[Welcomer] ✘ Eygeny покинул сервер (Kicked: Duplicate IP.​