So i've been updating my mod to 1.13.2, and i'm having some issues with either the Entity/EntityType registration process, or it's some other related issue.

I have some custom arrow entities, and this is how i create the EntityTypes:

 

public static final EntityType<EntitySittableBlock> SITTABLE_BLOCK;
	public static final EntityType<EntityExplodingArrow> EXPLODING_ARROW;
	public static final EntityType<EntityDiamondArrow> DIAMOND_ARROW;
	public static final EntityType<EntityEmeraldArrow> EMERALD_ARROW;
	public static final EntityType<EntityObsidianArrow> OBSIDIAN_ARROW;
	public static final EntityType<EntityGoldArrow> GOLD_ARROW;

	static
	{
		SITTABLE_BLOCK = createEntityType("sittable_block", EntitySittableBlock.class, EntitySittableBlock::new, 64, 1, false);
		EXPLODING_ARROW = createEntityType("exploding_arrow", EntityExplodingArrow.class, EntityExplodingArrow::new, 64, 1, true);
		DIAMOND_ARROW = createEntityType("diamond_arrow", EntityDiamondArrow.class, EntityDiamondArrow::new, 64, 1, true);
		EMERALD_ARROW = createEntityType("emerald_arrow", EntityEmeraldArrow.class, EntityEmeraldArrow::new, 64, 1, true);
		OBSIDIAN_ARROW = createEntityType("obsidian_arrow", EntityObsidianArrow.class, EntityObsidianArrow::new, 64, 1, true);
		GOLD_ARROW = createEntityType("gold_arrow", EntityGoldArrow.class, EntityGoldArrow::new, 64, 1, true);
	}

	private static <T extends Entity> EntityType<T> createEntityType(String id, Class<? extends T> entityClass, Function<? super World, ? extends T> factory, int range, int updateFrequency, boolean sendsVelocityUpdates)
	{
		EntityType<T> type = EntityType.Builder.create(entityClass, factory).tracker(range, updateFrequency, sendsVelocityUpdates).build(Constants.MODID + ":" + id);
		type.setRegistryName(new ResourceLocation(Constants.MODID, id));
		return type;
	}

	public static void register()
	{
		RegistryHandler.EntityTypes.add(SITTABLE_BLOCK);
		RegistryHandler.EntityTypes.add(EXPLODING_ARROW);
		RegistryHandler.EntityTypes.add(DIAMOND_ARROW);
		RegistryHandler.EntityTypes.add(EMERALD_ARROW);
		RegistryHandler.EntityTypes.add(OBSIDIAN_ARROW);
		RegistryHandler.EntityTypes.add(GOLD_ARROW);
	}

(The "register" method actually just inserts the types into a List in the RegistryHandler.EntityTypes class).

 

And then i use:

@Mod.EventBusSubscriber(bus = Mod.EventBusSubscriber.Bus.MOD)
	public static class EntityTypes
	{
		private static final List<EntityType<?>> ENTITY_TYPES = new LinkedList<>();

		public static <T extends Entity> void add(EntityType<T> type)
		{
			ENTITY_TYPES.add(type);
		}

		public static List<EntityType<?>> getEntityTypes()
		{
			return Collections.unmodifiableList(ENTITY_TYPES);
		}

		@SubscribeEvent
		public static void registerEntityTypes(final RegistryEvent.Register<EntityType<?>> event)
		{
			MEEntityTypes.register();
			ENTITY_TYPES.forEach(entityType -> event.getRegistry().register(entityType));
		}
	}

 

to actually register the types to the RegistryEvent.Register event.

 

However, whenever i try to fire one of the arrows, i get this error:

Spoiler

[05Mar2019 07:15:41.884] [Server thread/ERROR] [net.minecraft.entity.EntityTracker/]: "Silently" catching entity tracking error.
net.minecraft.crash.ReportedException: Adding entity to track
    at net.minecraft.entity.EntityTracker.track(EntityTracker.java:179) ~[?:?]
    at net.minecraft.entity.EntityTracker.track(EntityTracker.java:90) ~[?:?]
    at net.minecraft.world.ServerWorldEventHandler.onEntityAdded(SourceFile:42) ~[?:?]
    at net.minecraft.world.World.onEntityAdded(World.java:820) ~[?:?]
    at net.minecraft.world.WorldServer.onEntityAdded(WorldServer.java:780) ~[?:?]
    at net.minecraft.world.World.spawnEntity(World.java:813) ~[?:?]
    at net.minecraft.world.WorldServer.spawnEntity(WorldServer.java:740) ~[?:?]
    at com.nmg.me.item.MEItemBow.onPlayerStoppedUsing(MEItemBow.java:120) ~[?:?]
    at net.minecraft.item.ItemStack.onPlayerStoppedUsing(ItemStack.java:423) ~[?:?]
    at net.minecraft.entity.EntityLivingBase.stopActiveHand(EntityLivingBase.java:2320) ~[?:?]
    at net.minecraft.network.NetHandlerPlayServer.processPlayerDigging(NetHandlerPlayServer.java:794) ~[?:?]
    at net.minecraft.network.play.client.CPacketPlayerDigging.processPacket(SourceFile:40) ~[?:?]
    at net.minecraft.network.play.client.CPacketPlayerDigging.processPacket(SourceFile:10) ~[?:?]
    at net.minecraft.network.PacketThreadUtil.func_210405_a(SourceFile:10) ~[?:?]
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_191]
    at java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:266) [?:1.8.0_191]
    at java.util.concurrent.FutureTask.run(FutureTask.java) [?:1.8.0_191]
    at net.minecraft.util.Util.runTask(SourceFile:199) [?:?]
    at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:715) [?:?]
    at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:669) [?:?]
    at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:115) [?:?]
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:565) [?:?]
    at java.lang.Thread.run(Thread.java:748) [?:1.8.0_191]
Caused by: java.lang.IllegalArgumentException: Don't know how to add class com.nmg.me.entity.projectile.EntityObsidianArrow!
    at net.minecraft.entity.EntityTrackerEntry.createSpawnPacket(EntityTrackerEntry.java:508) ~[?:?]
    at net.minecraft.entity.EntityTrackerEntry.updatePlayerEntity(EntityTrackerEntry.java:318) ~[?:?]
    at net.minecraft.entity.EntityTrackerEntry.updatePlayers(EntityTrackerEntry.java:403) ~[?:?]
    at net.minecraft.entity.EntityTracker.track(EntityTracker.java:162) ~[?:?]
    ... 22 more

I've can't figure out how to fix this, since i don't even know what it means, so any help would be appreciated ?

Never mind, i'd just forgotten to set the correct EntityType for my Entity classes