NullReferenceException at PluginData+Preference.UpdateGradeTimerSolved
Failed to call hook 'OnStructureUpgrade' on plugin 'EnhancedHammer v2.0.6' 

Hi there, I keep getting this in the console when players try using the hammer.

Full error?

Failed to call hook 'OnPlayerDisconnected' on plugin 'EnhancedHammer v2.0.6' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.EnhancedHammer+PluginData+Preference.UpdateGradeTimer () [0x00027] in <31165b2de9ac4f7ba0c4eea1bc7b013d>:0
  at Oxide.Plugins.EnhancedHammer+PluginData+Preference.SetGrade (BuildingGrade+Enum grade) [0x0010e] in <31165b2de9ac4f7ba0c4eea1bc7b013d>:0
  at Oxide.Plugins.EnhancedHammer.OnPlayerDisconnected (BasePlayer player) [0x0000b] in <31165b2de9ac4f7ba0c4eea1bc7b013d>:0
  at Oxide.Plugins.EnhancedHammer.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x002d6] in <31165b2de9ac4f7ba0c4eea1bc7b013d>: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 :0
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in :0
Failed to call hook 'OnPlayerInput' on plugin 'EnhancedHammer v2.0.6' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.EnhancedHammer+PluginData+Preference.UpdateGradeTimer () [0x00027] in :0
at Oxide.Plugins.EnhancedHammer+PluginData+Preference.DoGrade (BuildingBlock block, System.Boolean suppressMessages) [0x00000] in :0
at Oxide.Plugins.EnhancedHammer.OnPlayerInput (BasePlayer player, InputState input) [0x00098] in :0
at Oxide.Plugins.EnhancedHammer.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00304] in :0
at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <3606d2af539c45e4b5c61658e6a8b307>:0
at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in :0
at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in :0


Merged post

Failed to call hook 'Unload' on plugin 'EnhancedHammer v2.0.6' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.EnhancedHammer+PluginData+Preference.UpdateGradeTimer () [0x00027] in :0
at Oxide.Plugins.EnhancedHammer+PluginData+Preference.SetGrade (BuildingGrade+Enum grade) [0x0010e] in :0
at Oxide.Plugins.EnhancedHammer.OnPlayerDisconnected (BasePlayer player) [0x0000b] in :0
at Oxide.Plugins.EnhancedHammer.Unload () [0x00017] in :0
at Oxide.Plugins.EnhancedHammer.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x000a1] in :0
at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <3606d2af539c45e4b5c61658e6a8b307>:0
at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in :0
at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in :0
Locked automatically