[Server thread/WARN]: Skipping Entity with id

So I've been creating custom entities lately and have come across this problem:

Code (Text):

[Server thread/WARN]: Skipping Entity with id HarvestGolem

I have found several people with a similar problem however the recommended fix tends to be the method below.

Spoiler: Registering Method

Code (Text):

    public void registerGolem(Class<? extends Entity> customClass, String name, int id) {
        try {
            List<Map<?, ?>> dataMap = new ArrayList<Map<?, ?>>();
            for (Field f : EntityTypes.class.getDeclaredFields()){
                if (f.getType().getSimpleName().equals(Map.class.getSimpleName())){
                    f.setAccessible(true);
                    dataMap.add((Map<?, ?>) f.get(null));
                }
            }
   
            if (dataMap.get(2).containsKey(id)){
                dataMap.get(0).remove(name);
                dataMap.get(2).remove(id);
            }
   
            Method method = EntityTypes.class.getDeclaredMethod("a", Class.class, String.class, int.class);
            method.setAccessible(true);
            method.invoke(null, customClass, name, id);
   
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }

The entity does not save with the world. When the chunk it is in is unloaded it gives the error Skipping Entity id. I have seen several people mentioning that it is a problem with registering. Is there anything wrong with my method of registering?

 

Ah, yes. I apologize for forgetting to add these details.
Here is how I register the entities:

Code (Text):

        registerGolem(HarvestGolem.class, "HarvestGolem", 54);
        registerGolem(SeekerGolem.class, "SeekerGolem", 54);
        registerGolem(GuardGolem.class, "GuardGolem", 54);
        registerGolem(MinerGolem.class, "MinerGolem", 54);
        registerGolem(BreederGolem.class, "BreederGolem", 54);

And I am using 1.8.8 which uses: net.minecraft.server.v1_8_R3

 

Not quite. The golem is a Zombie which is set to a baby.

EDIT: Here is a screenshot of the Harvest Golem:

 

I am not. You may check the log yourself if you wish:

Spoiler: Log

Code (Text):

[11:15:55] [Server thread/INFO]: Starting minecraft server version 1.8.8
[11:15:55] [Server thread/INFO]: Loading properties
[11:15:55] [Server thread/INFO]: Default game type: SURVIVAL
[11:15:55] [Server thread/INFO]: This server is running CraftBukkit version git-Spigot-e4d4710-e1ebe52 (MC: 1.8.8) (Implementing API version 1.8.8-R0.1-SNAPSHOT)
[11:15:56] [Server thread/INFO]: Debug logging is disabled
[11:15:56] [Server thread/INFO]: Server Ping Player Sample Count: 12
[11:15:56] [Server thread/INFO]: Using 4 threads for Netty based IO
[11:15:56] [Server thread/INFO]: Generating keypair
[11:15:56] [Server thread/INFO]: Starting Minecraft server on xxxxxxxxxxxxxxxxxx
[11:15:56] [Server thread/INFO]: Using epoll channel type
[11:15:56] [Server thread/INFO]: Set PluginClassLoader as parallel capable
[11:15:56] [Server thread/INFO]: [PermissionsEx] Loading PermissionsEx v1.23.4
[11:15:56] [Server thread/INFO]: [Golemry] Loading Golemry v0.1
[11:15:56] [Server thread/INFO]: [Essentials] Loading Essentials vTeamCity
[11:15:56] [Server thread/INFO]: [EssentialsChat] Loading EssentialsChat vTeamCity
[11:15:56] [Server thread/INFO]: **** Beginning UUID conversion, this may take A LONG time ****
[11:15:56] [Server thread/INFO]: Preparing level "map"
[11:15:56] [Server thread/INFO]: Preparing start region for level 0 (Seed: 7145718271811611538)
[11:15:57] [Server thread/INFO]: Preparing start region for level 1 (Seed: 7145718271811611538)
[11:15:58] [Server thread/INFO]: Preparing start region for level 2 (Seed: 7145718271811611538)
[11:15:58] [Server thread/INFO]: [PermissionsEx] Enabling PermissionsEx v1.23.4
[11:15:58] [Server thread/INFO]: [PermissionsEx] Initializing file backend
[11:15:58] [Server thread/INFO]: [PermissionsEx] Permissions file successfully reloaded
[11:15:58] [Server thread/INFO]: [Golemry] Enabling Golemry v0.1
[11:15:58] [Server thread/INFO]: [Essentials] Enabling Essentials vTeamCity
[11:15:58] [Server thread/INFO]: Bukkit version format changed. Version not checked.
[11:15:58] [Server thread/INFO]: git-Spigot-e4d4710-e1ebe52 (MC: 1.8.8)
[11:15:58] [Server thread/INFO]: 1.8.8-R0.1-SNAPSHOT
[11:15:58] [Server thread/INFO]: Using locale en_GB
[11:15:58] [Server thread/INFO]: Using locale en_GB
[11:15:58] [Server thread/INFO]: Essentials: Using PermissionsEx based permissions.
[11:15:58] [Server thread/INFO]: [EssentialsChat] Enabling EssentialsChat vTeamCity
[11:15:58] [Server thread/INFO]: Server permissions file permissions.yml is empty, ignoring it
[11:15:58] [Server thread/INFO]: Done (2.098s)! For help, type "help" or "?"
[11:18:39] [User Authenticator #1/INFO]: UUID of player xTheGamerPlayz is 3ea0aa33-e7d6-4f28-b2d9-6075bd5c60dc
[11:18:39] [Server thread/INFO]: xTheGamerPlayz[/66.172.68.177:56821] logged in with entity id 105 at ([map]-134.50037678192308, 144.0, -25.649476734752746)
[12:11:50] [Server thread/INFO]: xTheGamerPlayz issued server command: /sg harvest
 

 

EDIT: It seems part of my post was cut from my first post. Please look at it again

 

I changed them to this:

Code (Text):

    @SuppressWarnings({ "unchecked", "rawtypes" })
    public void registerGolem(Class<? extends Entity> clazz, String name, int id){
        try {
            //Remove the lines with // in front of them if you want to override default entities (You'd have to remove the default entity from the map first though).
            ((Map) getPrivateField("c", EntityTypes.class, null)).put(name, clazz);
            ((Map) getPrivateField("d", EntityTypes.class, null)).put(clazz, name);
            //((Map)getPrivateField("e", net.minecraft.server.v1_7_R4.EntityTypes.class, null)).put(Integer.valueOf(id), clazz);
            ((Map) getPrivateField("f", EntityTypes.class, null)).put(clazz, Integer.valueOf(id));
            //((Map)getPrivateField("g", net.minecraft.server.v1_7_R4.EntityTypes.class, null)).put(name, Integer.valueOf(id));
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }
 
    public Object getPrivateField(String fieldName, Class<? extends Object> clazz, Object object) {
        Field field;
        Object o = null;

        try
        {
            field = clazz.getDeclaredField(fieldName);

            field.setAccessible(true);

            o = field.get(object);
        }
        catch(NoSuchFieldException e)
        {
            e.printStackTrace();
        }
        catch(IllegalAccessException e)
        {
            e.printStackTrace();
        }

        return o;
    }

However when the server attempted to load them again I received the same warning:

Code (Text):

[12:39:53] [Server thread/WARN]: Skipping Entity with id HarvestGolem
[12:39:53] [Server thread/WARN]: Skipping Entity with id GuardGolem
[12:39:53] [Server thread/WARN]: Skipping Entity with id SeekerGolem
[12:39:53] [Server thread/WARN]: Skipping Entity with id MinerGolem
[12:39:53] [Server thread/WARN]: Skipping Entity with id BreederGolem

 

I don't want to override them and I may have to override entities at a later time, so I will leave them there as they do no harm. However just to ensure that there was no misunderstanding I did so. While I did not receive the warning the entity still did not appear from the saved chunk. However this may be because I did not override the default entity as I do not know how to do so. Could you explain it to me?

 

Well thanks for trying.