(16:19:53) | CraftQueueSaver was compiled successfully in 164ms
(16:19:53) | Failed to call hook 'Unload' on plugin 'CraftQueueSaver v1.1.4' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.CraftQueueSaver.SaveQueue (BasePlayer player) [0x00095] in <c6fad360b2574b8a9112a988917ea363>:0

  at Oxide.Plugins.CraftQueueSaver.OnPlayerDisconnected (BasePlayer player) [0x00000] in <c6fad360b2574b8a9112a988917ea363>:0

  at Oxide.Plugins.CraftQueueSaver.Unload () [0x00018] in <c6fad360b2574b8a9112a988917ea363>:0

  at Oxide.Plugins.CraftQueueSaver.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00206] in <c6fad360b2574b8a9112a988917ea363>:0

  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <31122a27a2414cd799150f8677cf39d4>:0

  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <c2afd8354b8b4f3ca451cf5a1aa111c3>:0

  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <c2afd8354b8b4f3ca451cf5a1aa111c3>:0
(16:19:53) | Unloaded plugin Craft Queue Saver v1.1.4 by Jake_Rich
(16:19:53) | Failed to call hook 'OnServerInitialized' on plugin 'CraftQueueSaver v1.1.4' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.CraftQueueSaver.LoadQueue (BasePlayer player) [0x0000b] in <4c9aaa92df1b4ad688ef4edec9e07c1a>:0

  at Oxide.Plugins.CraftQueueSaver.OnServerInitialized () [0x00018] in <4c9aaa92df1b4ad688ef4edec9e07c1a>:0

  at Oxide.Plugins.CraftQueueSaver.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x0008d] in <4c9aaa92df1b4ad688ef4edec9e07c1a>:0

  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <31122a27a2414cd799150f8677cf39d4>:0

  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <c2afd8354b8b4f3ca451cf5a1aa111c3>:0

  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <c2afd8354b8b4f3ca451cf5a1aa111c3>:0
(16:19:53) | Loaded plugin Craft Queue Saver v1.1.4 by Jake_Rich

hi, SavedCraftQueues_Database.json may be corrupted. unload the plugin, delete the datafile, and then load the plugin again.