Failed to call hook 'CanSamSiteShoot' on plugin 'SAMSiteAuth v2.0.1' (NullReferenceException: Object reference not set to an instance of an object)

  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000fb] in <4452f821def6406d834e4149849fe7ea>:0

  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <4452f821def6406d834e4149849fe7ea>:0

Please provide the full error from the log, what you've provided isn't enough to go on.