I created a Custom DeferredRegister Object and it worked fine. However, it crashes when I take that object as a constructor argument when creating an Item Registry Object. I think it's because the Custom Registry Object is generated later than the Item Registry Object is generated. Is there any way to solve this?

 

Mod main class :

@Mod("expansionmod")
public class ExpansionMod {
	public ExpansionMod() {
		ExpansionModMagics.MAGICS.makeRegistry("magic_registry", () -> new RegistryBuilder<>());
		ExpansionModMagics.MAGICS.register(FMLJavaModLoadingContext.get().getModEventBus());
		ExpansionModItems.ITEMS.register(FMLJavaModLoadingContext.get().getModEventBus());
	}
}

 

Mod items class :

public class ExpansionModItems {
	public static final DeferredRegister<Item> ITEMS = DeferredRegister.create(ForgeRegistries.ITEMS, "expansionmod");

	public static final RegistryObject<Item> SPELL = ITEMS.register("spel", () -> new SpellItem(new Item.Properties().group(ExpansionModItemGroups.EXPANSIONMOD_MAGIC), ExpansionModMagics.FIREBALL.get()));
}

 

Mod custom registry(Magic) class :

public class ExpansionModMagics {
	public static final DeferredRegister<Magic> MAGICS = DeferredRegister.create(Magic.class, ExpansionMod.MODID);

	public static final RegistryObject<Magic> FIREBALL = MAGICS.register("fireball", () -> new FireBallMagic(54));
}

 

Spell Item class :

public class SpellItem extends MagicalItem {
	public SpellItem(Properties properties, Magic magic) {
		super(properties, magic);
	}
}

 

Error log :

~
Description: Mod loading error has occurred

java.lang.Exception: Mod Loading has failed
	at net.minecraftforge.fml.CrashReportExtender.dumpModLoadingCrashReport(CrashReportExtender.java:85) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading}
	at net.minecraftforge.fml.client.ClientModLoader.completeModLoading(ClientModLoader.java:188) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading,pl:runtimedistcleaner:A}
	at net.minecraft.client.Minecraft.lambda$null$1(Minecraft.java:513) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
	at net.minecraft.util.Util.acceptOrElse(Util.java:323) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading}
	at net.minecraft.client.Minecraft.lambda$new$2(Minecraft.java:509) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
	at net.minecraft.client.gui.ResourceLoadProgressGui.render(ResourceLoadProgressGui.java:113) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading,pl:runtimedistcleaner:A}
	at net.minecraft.client.renderer.GameRenderer.updateCameraAndRender(GameRenderer.java:492) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
	at net.minecraft.client.Minecraft.runGameLoop(Minecraft.java:1002) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
	at net.minecraft.client.Minecraft.run(Minecraft.java:612) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
	at net.minecraft.client.main.Main.main(Main.java:184) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading,pl:runtimedistcleaner:A}
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_282] {}
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_282] {}
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_282] {}
	at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_282] {}
	at net.minecraftforge.userdev.FMLUserdevClientLaunchProvider.lambda$launchService$0(FMLUserdevClientLaunchProvider.java:52) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {}
	at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37) [modlauncher-8.0.9.jar:?] {}
	at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:54) [modlauncher-8.0.9.jar:?] {}
	at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:72) [modlauncher-8.0.9.jar:?] {}
	at cpw.mods.modlauncher.Launcher.run(Launcher.java:82) [modlauncher-8.0.9.jar:?] {}
	at cpw.mods.modlauncher.Launcher.main(Launcher.java:66) [modlauncher-8.0.9.jar:?] {}
	at net.minecraftforge.userdev.LaunchTesting.main(LaunchTesting.java:105) [forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {}


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Thread: Render thread
Stacktrace:
	at java.util.Objects.requireNonNull(Objects.java:290) ~[?:1.8.0_282] {}
-- MOD expansionmod --
Details:
	Mod File: main
	Failure message: Expansion Mod (expansionmod) encountered an error during the load_registries event phase
		java.lang.NullPointerException: Registry Object not present: expansionmod:fireball
	Mod Version: NONE
	Mod Issue URL: NOT PROVIDED
	Exception message: java.lang.NullPointerException: Registry Object not present: expansionmod:fireball
Stacktrace:
	at java.util.Objects.requireNonNull(Objects.java:290) ~[?:1.8.0_282] {}
	at net.minecraftforge.fml.RegistryObject.get(RegistryObject.java:120) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading}
	at io.github.zemelua.expansionmod.item.ExpansionModItems.lambda$static$23(ExpansionModItems.java:61) ~[main/:?] {re:classloading}
	at net.minecraftforge.registries.DeferredRegister.lambda$register$0(DeferredRegister.java:124) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading}
	at net.minecraftforge.registries.DeferredRegister.addEntries(DeferredRegister.java:200) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading}
	at net.minecraftforge.registries.DeferredRegister.access$000(DeferredRegister.java:61) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading}
	at net.minecraftforge.registries.DeferredRegister$EventDispatcher.handleEvent(DeferredRegister.java:172) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading}
	at net.minecraftforge.eventbus.ASMEventHandler_2_EventDispatcher_handleEvent_Register.invoke(.dynamic) ~[?:?] {}
	at net.minecraftforge.eventbus.ASMEventHandler.invoke(ASMEventHandler.java:85) ~[eventbus-4.0.0.jar:?] {}
	at net.minecraftforge.eventbus.EventBus.post(EventBus.java:302) ~[eventbus-4.0.0.jar:?] {}
	at net.minecraftforge.eventbus.EventBus.post(EventBus.java:283) ~[eventbus-4.0.0.jar:?] {}
	at net.minecraftforge.fml.javafmlmod.FMLModContainer.acceptEvent(FMLModContainer.java:120) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:36.0] {re:classloading}
	at net.minecraftforge.fml.ModContainer.lambda$buildTransitionHandler$4(ModContainer.java:121) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading}
	at java.util.concurrent.CompletableFuture$AsyncRun.run(CompletableFuture.java:1640) ~[?:1.8.0_282] {}
	at net.minecraftforge.fml.ModWorkManager$SyncExecutor.driveOne(ModWorkManager.java:56) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading}
	at net.minecraftforge.fml.ModWorkManager$DrivenExecutor.drive(ModWorkManager.java:40) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading}
	at net.minecraftforge.fml.ModLoader.waitForTransition(ModLoader.java:243) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading}
	at net.minecraftforge.fml.ModLoader.dispatchAndHandleError(ModLoader.java:230) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading}
	at net.minecraftforge.fml.ModLoader.gatherAndInitializeMods(ModLoader.java:196) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading}
	at net.minecraftforge.fml.client.ClientModLoader.lambda$begin$1(ClientModLoader.java:103) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading,pl:runtimedistcleaner:A}
	at net.minecraftforge.fml.client.ClientModLoader.lambda$createRunnableWithCatch$4(ClientModLoader.java:123) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading,pl:runtimedistcleaner:A}
	at net.minecraftforge.fml.client.ClientModLoader.begin(ClientModLoader.java:103) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading,pl:runtimedistcleaner:A}
	at net.minecraft.client.Minecraft.<init>(Minecraft.java:442) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
	at net.minecraft.client.main.Main.main(Main.java:149) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {re:classloading,pl:runtimedistcleaner:A}
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_282] {}
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_282] {}
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_282] {}
	at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_282] {}
	at net.minecraftforge.userdev.FMLUserdevClientLaunchProvider.lambda$launchService$0(FMLUserdevClientLaunchProvider.java:52) ~[forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {}
	at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37) [modlauncher-8.0.9.jar:?] {}
	at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:54) [modlauncher-8.0.9.jar:?] {}
	at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:72) [modlauncher-8.0.9.jar:?] {}
	at cpw.mods.modlauncher.Launcher.run(Launcher.java:82) [modlauncher-8.0.9.jar:?] {}
	at cpw.mods.modlauncher.Launcher.main(Launcher.java:66) [modlauncher-8.0.9.jar:?] {}
	at net.minecraftforge.userdev.LaunchTesting.main(LaunchTesting.java:105) [forge-1.16.5-36.0.7_mapped_snapshot_20201028-1.16.3-recomp.jar:?] {}
~

 

21 minutes ago, Zemelua said:

public static final RegistryObject<Item> SPELL = ITEMS.register("spel", () -> new SpellItem(new Item.Properties().group(ExpansionModItemGroups.EXPANSIONMOD_MAGIC), ExpansionModMagics.FIREBALL.get()));

You need to hold a supplied instance of the registry object as items will always be registered first. Luckily, RegistryObjects are supplied instances of registry objects.

sorry, I'm not sure. I think it means that the registry of the item is done before the registry of magic, but where and what should I do?

I solved it by giving SpellItem a RegistryObject <Magic> instead of the Magic class type. Thank you!