failed to give players belongings back

Failed to call hook 'EMEndEvent' on plugin 'EventHelper v1.0.15' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.EventHelper.GetRestoreItem (BasePlayer player, ItemContainer container, Oxide.Plugins.EventHelper+ItemInfo savedItem) [0x00172] in <38fea81daa01435ba0121226e2928244>:0 
  at Oxide.Plugins.EventHelper.RestoreItems (BasePlayer player, System.Boolean strip) [0x00098] in <38fea81daa01435ba0121226e2928244>:0 
  at Oxide.Plugins.EventHelper.EMPlayerLeaveEvent (BasePlayer player, System.String eventName, System.Boolean manually_left) [0x00088] in <38fea81daa01435ba0121226e2928244>:0 
  at Oxide.Plugins.EventHelper.EMEndEvent (System.String eventName) [0x0004e] in <38fea81daa01435ba0121226e2928244>:0 
  at Oxide.Plugins.EventHelper.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x01524] in <38fea81daa01435ba0121226e2928244>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <42f9bedc659b4f4786eb778d3cd58968>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000de] in <8cb2d664f1574f2b96d53f1c1869d96a>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <8cb2d664f1574f2b96d53f1c1869d96a>:0