Hello,

 

I update my mod from 1.15.2 (which works perfectly) to 1.16.4.

In my mod, there are items to spawn different custom mobs.

The problem is than they don't spawn and I have message like in the title :"Error executing task on Server" :

 

[16:43:36] [Server thread/FATAL] [minecraft/ThreadTaskExecutor]: Error executing task on Server
java.lang.NullPointerException: null
	at net.minecraft.entity.ai.attributes.AttributeModifierManager.getAttributeValue(AttributeModifierManager.java:67) ~[forge:?] {re:classloading}
	at net.minecraft.entity.LivingEntity.getAttributeValue(LivingEntity.java:1849) ~[forge:?] {re:classloading}
	at net.minecraft.entity.LivingEntity.getMaxHealth(LivingEntity.java:1610) ~[forge:?] {re:classloading}
	at net.minecraft.entity.LivingEntity.<init>(LivingEntity.java:209) ~[forge:?] {re:classloading}
	at net.minecraft.entity.MobEntity.<init>(MobEntity.java:108) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.entity.CreatureEntity.<init>(CreatureEntity.java:13) ~[forge:?] {re:classloading}
	at net.mattbaker.guardscraft.enemies.bandit.BanditEntity.<init>(BanditEntity.java:39) ~[?:?] {re:classloading}
	at net.minecraft.entity.EntityType.create(EntityType.java:448) ~[forge:?] {re:classloading}
	at net.minecraft.entity.EntityType.create(EntityType.java:332) ~[forge:?] {re:classloading}
	at net.minecraft.entity.EntityType.spawn(EntityType.java:321) ~[forge:?] {re:classloading}
	at net.minecraft.entity.EntityType.spawn(EntityType.java:316) ~[forge:?] {re:classloading}
	at net.mattbaker.guardscraft.enemies.bandit.BanditSpawn.onItemUse(BanditSpawn.java:77) ~[?:?] {re:classloading}
	at net.minecraftforge.common.ForgeHooks.onPlaceItemIntoWorld(ForgeHooks.java:613) ~[forge:?] {re:classloading}
	at net.minecraft.item.ItemStack.onItemUse(ItemStack.java:191) ~[forge:?] {re:classloading}
	at net.minecraft.server.management.PlayerInteractionManager.func_219441_a(PlayerInteractionManager.java:359) ~[forge:?] {re:classloading}
	at net.minecraft.network.play.ServerPlayNetHandler.processTryUseItemOnBlock(ServerPlayNetHandler.java:986) ~[forge:?] {re:classloading}
	at net.minecraft.network.play.client.CPlayerTryUseItemOnBlockPacket.processPacket(CPlayerTryUseItemOnBlockPacket.java:45) ~[forge:?] {re:classloading}
	at net.minecraft.network.play.client.CPlayerTryUseItemOnBlockPacket.processPacket(CPlayerTryUseItemOnBlockPacket.java:12) ~[forge:?] {re:classloading}
	at net.minecraft.network.PacketThreadUtil.lambda$checkThreadAndEnqueue$0(PacketThreadUtil.java:19) ~[forge:?] {re:classloading}
	at net.minecraft.util.concurrent.TickDelayedTask.run(TickDelayedTask.java:20) ~[forge:?] {re:classloading}
	at net.minecraft.util.concurrent.ThreadTaskExecutor.run(ThreadTaskExecutor.java:139) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.util.concurrent.RecursiveEventLoop.run(RecursiveEventLoop.java:22) ~[forge:?] {re:classloading}
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:758) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:159) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.util.concurrent.ThreadTaskExecutor.driveOne(ThreadTaskExecutor.java:109) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.server.MinecraftServer.driveOneInternal(MinecraftServer.java:741) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.server.MinecraftServer.driveOne(MinecraftServer.java:735) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.util.concurrent.ThreadTaskExecutor.drainTasks(ThreadTaskExecutor.java:97) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.server.MinecraftServer.runScheduledTasks(MinecraftServer.java:720) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.server.MinecraftServer.func_240802_v_(MinecraftServer.java:667) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.server.MinecraftServer.lambda$startServer$0(MinecraftServer.java:233) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_271] {}

 

Here my code for the item (based on SpawnEggItem.class)

 

public class BanditSpawn extends Item
{
	public BanditSpawn()
	{
    	super(new Item.Properties().maxStackSize(1).group(GuardsCraft.setup.itemGroup));
	}

    @Override
    public ActionResultType onItemUse(ItemUseContext context)
    {
        World world = context.getWorld();
        
        if(!(world instanceof ServerWorld))
        {
            return ActionResultType.SUCCESS;
        }
        else
        {
            ItemStack itemstack = context.getItem();
            BlockPos blockpos = context.getPos();
            Direction direction = context.getFace();
            BlockState blockstate = world.getBlockState(blockpos);
            TileEntity tileentity = world.getTileEntity(blockpos);
            
            if(blockstate.isIn(Blocks.SPAWNER))
            {
                if(tileentity instanceof MobSpawnerTileEntity)
                {
                    AbstractSpawner abstractspawner = ((MobSpawnerTileEntity)tileentity).getSpawnerBaseLogic();
                    abstractspawner.setEntityType(Registration.BANDIT.get());
                    tileentity.markDirty();
                    world.notifyBlockUpdate(blockpos, blockstate, blockstate, 3);    
                    itemstack.shrink(1);
                    return ActionResultType.CONSUME;
                }
            }
            
            BlockPos blockpos1;
            
            if(blockstate.getCollisionShape(world, blockpos).isEmpty())
            {
                blockpos1 = blockpos;
            }
            else
            {
                blockpos1 = blockpos.offset(direction);
            }
            
            if(Registration.BANDIT.get().spawn((ServerWorld) world, itemstack, context.getPlayer(), blockpos1, SpawnReason.SPAWN_EGG, true, !Objects.equals(blockpos, blockpos1) && direction == Direction.UP) != null) 
            {
                itemstack.shrink(1);
            }
            
            return ActionResultType.SUCCESS;
        }
    }
}

 

My Registration :

 

public class Registration 
{
	private static final DeferredRegister<Item> ITEMS = DeferredRegister.create(ForgeRegistries.ITEMS, GuardsCraft.MOD_ID);
	
	public static void init() 
	{
		ITEMS.register(FMLJavaModLoadingContext.get().getModEventBus());
	}

	public static final RegistryObject<EntityType<BanditEntity>> BANDIT = ENTITIES.register("bandit", () -> EntityType.Builder.create(BanditEntity::new, EntityClassification.CREATURE).setShouldReceiveVelocityUpdates(false).build("bandit"));

	public static final RegistryObject<BanditSpawn> BANDIT_EGG = ITEMS.register("bandit_egg", BanditSpawn::new);
}

 

Maybe more code if needed.

 

Thanks.

 

mattbaker

 

Edited January 8, 20214 yr by mattbaker

That works. Thanks you.

 

private void setup(final FMLCommonSetupEvent event)
{
	event.enqueueWork(() ->
	{	
		GlobalEntityTypeAttributes.put(Registration.BANDIT.get(), BanditEntity.setCustomAttributes().create());
	});
}