NullReferenceException

Failed to call hook 'OnEntityTakeDamage' on plugin 'BossMonster v2.2.2' (NullReferenceException: Object reference not set to an instance of an object.)
  at Oxide.Plugins.BossMonster.OnEntityTakeDamage (ScientistNPC entity, HitInfo info) [0x00020] in <999b8a54bdad4c19a46a4ae302b3643f>:0 
  at Oxide.Plugins.BossMonster.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x0091c] in <999b8a54bdad4c19a46a4ae302b3643f>: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 <db058accaef24d86af67c0d18d641acb>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <db058accaef24d86af67c0d18d641acb>:0 
NullReferenceException: Object reference not set to an instance of an object

Hello, this is rare issue, and its already on roadmap, try change this in BossMonster.cs (default string commented, next string new with additional check)
 

        private object OnEntityTakeDamage(ScientistNPC entity, HitInfo info)
        {
            //if (entity == null || info == null) return null;
            if (entity == null || info == null || entity.net == null) return null;
            if (_controllers.ContainsKey(entity.net.ID.Value))
            {