Failed to call hook 'SilCommand' on plugin 'SignArtist v1.4.1' (NullReferenceException: Object reference not set to an instance of an object)

at Oxide.Plugins.SignArtist.HasCooldown (BasePlayer player) [0x00006] in <7159a9e2de94441094c541cfa1911ca3>:0

at Oxide.Plugins.SignArtist.SilCommand (Oxide.Core.Libraries.Covalence.IPlayer iplayer, System.String command, System.String[] args) [0x00030] in <7159a9e2de94441094c541cfa1911ca3>:0

at Oxide.Plugins.SignArtist.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x0022a] in <7159a9e2de94441094c541cfa1911ca3>:0

at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <23ba99f131254889867c71f0bd137b1d>:0

at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <157a94ee66ab4a7991faecd1eb84be3b>:0

at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <157a94ee66ab4a7991faecd1eb84be3b>:0