[1.19] FriendlyByteBuff is null in constructor when using IForgeMenu.create for registration of custom menu type

[Adil Yilan]

Hi,

I have implemented custom chest, but I am getting a very strange error when the menu should appear.

This is how menu is registered:

public final class ContainerMenuTypes {

	private ContainerMenuTypes() {}
	
	public static final DeferredRegister<MenuType<?>> REGISTRY =
			DeferredRegister.create(ForgeRegistries.MENU_TYPES, ExperimentalMod.MODID);
	
	public static final RegistryObject<MenuType<VikingChestMenu>> VIKING_CHEST =
			REGISTRY.register("viking_chest", () -> IForgeMenuType.create(VikingChestMenu::new));

}

 

And this is how constructor looks like:

	// This constructor is required by forge to register menu type.
	public VikingChestMenu(int containerId, Inventory inventory, FriendlyByteBuf buff) {
		this(containerId, inventory, inventory.player.level.getBlockEntity(buff.readBlockPos()));
	}

 

So when I click on the chest, this error occurs:

 

[15:31:15] [Render thread/ERROR] [minecraft/BlockableEventLoop]: Error executing task on Client
java.lang.NullPointerException: Cannot invoke "net.minecraft.network.FriendlyByteBuf.readBlockPos()" because "buff" is null
	at ba.appimpact.minecraft.experimental.common.menu.container.VikingChestMenu.<init>(VikingChestMenu.java:83) ~[%23186!/:?] {re:classloading}
	at net.minecraftforge.network.IContainerFactory.create(IContainerFactory.java:20) ~[forge-1.19-41.0.110_mapped_parchment_1.18.2-2022.07.17-1.19.jar%23180%23187!/:?] {re:classloading}
	at net.minecraft.world.inventory.MenuType.create(MenuType.java:44) ~[forge-1.19-41.0.110_mapped_parchment_1.18.2-2022.07.17-1.19.jar%23181!/:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.client.gui.screens.MenuScreens$ScreenConstructor.fromPacket(MenuScreens.java:115) ~[forge-1.19-41.0.110_mapped_parchment_1.18.2-2022.07.17-1.19.jar%23181!/:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
	at net.minecraft.client.gui.screens.MenuScreens.lambda$create$0(MenuScreens.java:43) ~[forge-1.19-41.0.110_mapped_parchment_1.18.2-2022.07.17-1.19.jar%23181!/:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
	at java.util.Optional.ifPresent(Optional.java:178) ~[?:?] {}
	at net.minecraft.client.gui.screens.MenuScreens.create(MenuScreens.java:43) ~[forge-1.19-41.0.110_mapped_parchment_1.18.2-2022.07.17-1.19.jar%23181!/:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
	at net.minecraft.client.multiplayer.ClientPacketListener.handleOpenScreen(ClientPacketListener.java:979) ~[forge-1.19-41.0.110_mapped_parchment_1.18.2-2022.07.17-1.19.jar%23181!/:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
	at net.minecraft.network.protocol.game.ClientboundOpenScreenPacket.handle(ClientboundOpenScreenPacket.java:37) ~[forge-1.19-41.0.110_mapped_parchment_1.18.2-2022.07.17-1.19.jar%23181!/:?] {re:classloading}
	at net.minecraft.network.protocol.game.ClientboundOpenScreenPacket.handle(ClientboundOpenScreenPacket.java:11) ~[forge-1.19-41.0.110_mapped_parchment_1.18.2-2022.07.17-1.19.jar%23181!/:?] {re:classloading}
	at net.minecraft.network.protocol.PacketUtils.lambda$ensureRunningOnSameThread$0(PacketUtils.java:22) ~[forge-1.19-41.0.110_mapped_parchment_1.18.2-2022.07.17-1.19.jar%23181!/:?] {re:classloading}
	at net.minecraft.util.thread.BlockableEventLoop.doRunTask(BlockableEventLoop.java:157) ~[forge-1.19-41.0.110_mapped_parchment_1.18.2-2022.07.17-1.19.jar%23181!/:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.util.thread.ReentrantBlockableEventLoop.doRunTask(ReentrantBlockableEventLoop.java:23) ~[forge-1.19-41.0.110_mapped_parchment_1.18.2-2022.07.17-1.19.jar%23181!/:?] {re:classloading}
	at net.minecraft.util.thread.BlockableEventLoop.pollTask(BlockableEventLoop.java:131) ~[forge-1.19-41.0.110_mapped_parchment_1.18.2-2022.07.17-1.19.jar%23181!/:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.util.thread.BlockableEventLoop.runAllTasks(BlockableEventLoop.java:116) ~[forge-1.19-41.0.110_mapped_parchment_1.18.2-2022.07.17-1.19.jar%23181!/:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.client.Minecraft.runTick(Minecraft.java:1041) ~[forge-1.19-41.0.110_mapped_parchment_1.18.2-2022.07.17-1.19.jar%23181!/:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
	at net.minecraft.client.Minecraft.run(Minecraft.java:669) ~[forge-1.19-41.0.110_mapped_parchment_1.18.2-2022.07.17-1.19.jar%23181!/:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
	at net.minecraft.client.main.Main.main(Main.java:206) ~[forge-1.19-41.0.110_mapped_parchment_1.18.2-2022.07.17-1.19.jar%23181!/:?] {re:classloading,pl:runtimedistcleaner:A}
	at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?] {}
	at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[?:?] {}
	at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?] {}
	at java.lang.reflect.Method.invoke(Method.java:568) ~[?:?] {}
	at net.minecraftforge.fml.loading.targets.ForgeClientUserdevLaunchHandler.lambda$launchService$0(ForgeClientUserdevLaunchHandler.java:25) ~[fmlloader-1.19-41.0.110.jar%2394!/:?] {}
	at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:30) [modlauncher-10.0.8.jar%23106!/:?] {}
	at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:53) [modlauncher-10.0.8.jar%23106!/:?] {}
	at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:71) [modlauncher-10.0.8.jar%23106!/:?] {}
	at cpw.mods.modlauncher.Launcher.run(Launcher.java:106) [modlauncher-10.0.8.jar%23106!/:?] {}
	at cpw.mods.modlauncher.Launcher.main(Launcher.java:77) [modlauncher-10.0.8.jar%23106!/:?] {}
	at cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:26) [modlauncher-10.0.8.jar%23106!/:?] {}
	at cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:23) [modlauncher-10.0.8.jar%23106!/:?] {}
	at cpw.mods.bootstraplauncher.BootstrapLauncher.main(BootstrapLauncher.java:141) [bootstraplauncher-1.1.2.jar:?] {}

 

For some reason, FriendlyByteBuf buff is null in constructor and I need it to access block entity so that rest of the code can execute.

Any ideas what could be wrong here?

 

[Luis_ST]

Please show the code where you open the menu.

[Adil Yilan]

This is the use method on VikingChestBlock class:

	@Override
	public InteractionResult use(BlockState blockState, Level level, BlockPos blockPos, Player player, InteractionHand hand, BlockHitResult blockHitResult) {
		
		// IF: Code is executing on logical client.
		if(level.isClientSide) {
			// Do nothing.
			return InteractionResult.SUCCESS;
		}
		
		// Get block entity at the position where block was used.
		BlockEntity blockEntity = level.getBlockEntity(blockPos);
		
        if (blockEntity instanceof VikingChestBlockEntity) {

        	// Open menu.
			player.openMenu((VikingChestBlockEntity)blockEntity);
			
         }
		
		return InteractionResult.CONSUME;
	}

 

I also used this, but didn't work either:

 

@Override
	public InteractionResult use(BlockState blockState, Level level, BlockPos blockPos, Player player, InteractionHand hand, BlockHitResult blockHitResult) {
		
		// IF: Code is executing on logical client.
		if(level.isClientSide) {
			// Do nothing.
			return InteractionResult.SUCCESS;
		}
		
		// Get menu provider reference.
		MenuProvider menuprovider = this.getMenuProvider(blockState, level, blockPos);

		// IF: Menu provider is defined.
		if (menuprovider != null) {
			
			// Open menu.
			player.openMenu(menuprovider);
			
		}

		return InteractionResult.CONSUME;
	}

 

 

[Adil Yilan]

Thanks @diesieben07 and @Luis_ST, you've helped me a lot as usual.

 

It works great now with this code:

 

@Override
      public InteractionResult use(BlockState blockState, Level level, BlockPos blockPos, Player player, InteractionHand hand, BlockHitResult blockHitResult) {
		
		// IF: Code is executing on logical client.
		if(level.isClientSide) {
			// Do nothing.
			return InteractionResult.SUCCESS;
		}
		
		// Get block entity at the block location.
		BlockEntity blockEntity = level.getBlockEntity(blockPos);
		
		// IF: block entity is matching.
		if (blockEntity instanceof VikingChestBlockEntity) {
			
			// Cast player to ServerPlayer.
			ServerPlayer serverPlayer = (ServerPlayer) player;
			
			// Cast block entity to VikingChestBlockEntity.
			VikingChestBlockEntity vikingChestBlockEntity = (VikingChestBlockEntity)blockEntity;

			// Open menu.
            NetworkHooks.openScreen(serverPlayer, vikingChestBlockEntity, blockPos);
		}

		return InteractionResult.CONSUME;
	}