Failed to call hook 'OnPlayerDisconnected' on plugin 'Bank v1.0.52' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.Bank.OnPlayerDisconnected (BasePlayer player) [0x0000c] in <ae4900e4153340188f231a633233b28f>:0
  at Oxide.Plugins.Bank.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00620] in <ae4900e4153340188f231a633233b28f>:0
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <1e2d7ad0801a4037ab6a24578c814b54>:0
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <1fe782f4b27a43ae85d29ebb2d56c007>:0
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <1fe782f4b27a43ae85d29ebb2d56c007>:0

Getting this error on one of my servers. any ideas?

Failed to call hook 'OnPlayerDisconnected' on plugin 'Bank v1.0.52' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.Bank.OnPlayerDisconnected (BasePlayer player) [0x0000c] in <1dcb7db61264437f886db8c1d7db740c>:0
  at Oxide.Plugins.Bank.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00620] in <1dcb7db61264437f886db8c1d7db740c>:0
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <80b90e8213db44b29ec2d4111764172c>:0
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <ec05e0208c9149bba43236ca58fea105>:0
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <ec05e0208c9149bba43236ca58fea105>:0