[Solved][1.16.1]Client works, but server crashes at packet handler.

[kyazuki]

runClient worked, but runServer crashed.

How do I fix?

 

Code:

https://github.com/kyazuki/DietMod/tree/37d228d98922fb2d498414dcd2db04f744a2b8f1

Error:

Quote

[0882020 03:56:44.493] [main/INFO] [cpw.mods.modlauncher.Launcher/MODLAUNCHER]: ModLauncher running: args [--gameDir, ., --launchTarget, fmluserdevserver, --fml.mcpVersion, 20200625.160719, --fml.mcVersion, 1.16.1, --fml.forgeGroup, net.minecraftforge, --fml.forgeVersion, 32.0.75]
[0882020 03:56:44.497] [main/INFO] [cpw.mods.modlauncher.Launcher/MODLAUNCHER]: ModLauncher 5.1.2+70+master.2845bb9 starting: java version 1.8.0_231 by Oracle Corporation
[0882020 03:56:44.847] [main/INFO] [net.minecraftforge.fml.loading.FixSSL/CORE]: Added Lets Encrypt root certificates as additional trust
[0882020 03:56:44.883] [main/INFO] [mixin/]: SpongePowered MIXIN Subsystem Version=0.8 Source=file:/C:/Users/kazuki/.gradle/caches/modules-2/files-2.1/org.spongepowered/mixin/0.8/dbe9e5db694a7c3cd644d5bb98f8a21295c75048/mixin-0.8.jar Service=ModLauncher Env=SERVER
[0882020 03:56:46.193] [main/INFO] [cpw.mods.modlauncher.LaunchServiceHandler/MODLAUNCHER]: Launching target 'fmluserdevserver' with arguments [--gameDir, .]
[0882020 03:57:02.308] [modloading-worker-1/INFO] [net.minecraftforge.common.ForgeMod/FORGEMOD]: Forge mod loading, version 32.0.75, for MC 1.16.1 with MCP 20200625.160719
[0882020 03:57:02.308] [modloading-worker-1/INFO] [net.minecraftforge.common.MinecraftForge/FORGE]: MinecraftForge v32.0.75 Initialized
[0882020 03:57:02.590] [modloading-worker-2/FATAL] [net.minecraftforge.fml.loading.RuntimeDistCleaner/DISTXFORM]: Attempted to load class net/minecraft/client/entity/player/ClientPlayerEntity for invalid dist DEDICATED_SERVER
[0882020 03:57:02.591] [modloading-worker-2/ERROR] [net.minecraftforge.fml.javafmlmod.FMLModContainer/LOADING]: Failed to create mod instance. ModID: dietmod, class com.github.kyazuki.dietmod.DietMod
java.lang.RuntimeException: Attempted to load class net/minecraft/client/entity/player/ClientPlayerEntity for invalid dist DEDICATED_SERVER
    at net.minecraftforge.fml.loading.RuntimeDistCleaner.processClass(RuntimeDistCleaner.java:71) ~[forge-1.16.1-32.0.75_mapped_snapshot_20200723-1.16.1-launcher.jar:32.0]
    at cpw.mods.modlauncher.serviceapi.ILaunchPluginService.processClass(ILaunchPluginService.java:103) ~[modlauncher-5.1.2.jar:5.1.2+70+master.2845bb9]
    at cpw.mods.modlauncher.LaunchPluginHandler.offerClassNodeToPlugins(LaunchPluginHandler.java:85) ~[modlauncher-5.1.2.jar:?]
    at cpw.mods.modlauncher.ClassTransformer.transform(ClassTransformer.java:115) ~[modlauncher-5.1.2.jar:?]
    at cpw.mods.modlauncher.TransformingClassLoader$DelegatedClassLoader.findClass(TransformingClassLoader.java:247) ~[modlauncher-5.1.2.jar:?]
    at cpw.mods.modlauncher.TransformingClassLoader.loadClass(TransformingClassLoader.java:134) ~[modlauncher-5.1.2.jar:?]
    at cpw.mods.modlauncher.TransformingClassLoader.loadClass(TransformingClassLoader.java:96) ~[modlauncher-5.1.2.jar:?]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:351) ~[?:1.8.0_231]
    at java.lang.invoke.MethodHandleNatives.resolve(Native Method) ~[?:1.8.0_231]
    at java.lang.invoke.MemberName$Factory.resolve(MemberName.java:975) ~[?:1.8.0_231]
    at java.lang.invoke.MemberName$Factory.resolveOrFail(MemberName.java:1000) ~[?:1.8.0_231]
    at java.lang.invoke.MethodHandles$Lookup.resolveOrFail(MethodHandles.java:1394) ~[?:1.8.0_231]
    at java.lang.invoke.MethodHandles$Lookup.linkMethodHandleConstant(MethodHandles.java:1750) ~[?:1.8.0_231]
    at java.lang.invoke.MethodHandleNatives.linkMethodHandleConstant(MethodHandleNatives.java:477) ~[?:1.8.0_231]
    at com.github.kyazuki.dietmod.network.PacketHandler.register(PacketHandler.java:21) ~[?:?]
    at com.github.kyazuki.dietmod.DietMod.<init>(DietMod.java:25) ~[?:?]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[?:1.8.0_231]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[?:1.8.0_231]
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[?:1.8.0_231]
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[?:1.8.0_231]
    at java.lang.Class.newInstance(Class.java:442) ~[?:1.8.0_231]
    at net.minecraftforge.fml.javafmlmod.FMLModContainer.constructMod(FMLModContainer.java:131) ~[?:32.0]
    at java.util.function.Consumer.lambda$andThen$0(Consumer.java:65) ~[?:1.8.0_231]
    at java.util.function.Consumer.lambda$andThen$0(Consumer.java:65) ~[?:1.8.0_231]
    at net.minecraftforge.fml.ModContainer.transitionState(ModContainer.java:112) ~[?:?]
    at net.minecraftforge.fml.ModList.lambda$null$10(ModList.java:135) ~[?:?]
    at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184) [?:1.8.0_231]
    at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1382) [?:1.8.0_231]
    at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:482) [?:1.8.0_231]
    at java.util.stream.ForEachOps$ForEachTask.compute(ForEachOps.java:291) [?:1.8.0_231]
    at java.util.concurrent.CountedCompleter.exec(CountedCompleter.java:731) [?:1.8.0_231]
    at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289) [?:1.8.0_231]
    at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056) [?:1.8.0_231]
    at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692) [?:1.8.0_231]
    at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157) [?:1.8.0_231]
[0882020 03:57:02.669] [main/FATAL] [net.minecraftforge.fml.ModLoader/LOADING]: Failed to complete lifecycle event CONSTRUCT, 1 errors found
[0882020 03:57:02.669] [main/FATAL] [net.minecraft.server.Main/]: Failed to start the minecraft server
net.minecraftforge.fml.LoadingFailedException: Loading errors encountered: [
    Diet Mod (dietmod) has failed to load correctly
§7Attempted to load class net/minecraft/client/entity/player/ClientPlayerEntity for invalid dist DEDICATED_SERVER
]
    at net.minecraftforge.fml.ModLoader.dispatchAndHandleError(ModLoader.java:218) ~[forge-1.16.1-32.0.75_mapped_snapshot_20200723-1.16.1-recomp.jar:?]
    at net.minecraftforge.fml.ModLoader.gatherAndInitializeMods(ModLoader.java:200) ~[forge-1.16.1-32.0.75_mapped_snapshot_20200723-1.16.1-recomp.jar:?]
    at net.minecraftforge.fml.server.ServerModLoader.load(ServerModLoader.java:49) ~[forge-1.16.1-32.0.75_mapped_snapshot_20200723-1.16.1-recomp.jar:?]
    at net.minecraft.server.Main.main(Main.java:95) ~[forge-1.16.1-32.0.75_mapped_snapshot_20200723-1.16.1-recomp.jar:?]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_231]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_231]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_231]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_231]
    at net.minecraftforge.userdev.FMLUserdevServerLaunchProvider.lambda$launchService$0(FMLUserdevServerLaunchProvider.java:54) ~[forge-1.16.1-32.0.75_mapped_snapshot_20200723-1.16.1-recomp.jar:?]
    at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37) [modlauncher-5.1.2.jar:?]
    at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:54) [modlauncher-5.1.2.jar:?]
    at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:72) [modlauncher-5.1.2.jar:?]
    at cpw.mods.modlauncher.Launcher.run(Launcher.java:81) [modlauncher-5.1.2.jar:?]
    at cpw.mods.modlauncher.Launcher.main(Launcher.java:65) [modlauncher-5.1.2.jar:?]
    at net.minecraftforge.userdev.LaunchTesting.main(LaunchTesting.java:105) [forge-1.16.1-32.0.75_mapped_snapshot_20200723-1.16.1-recomp.jar:?]
 

 

Edited August 9, 2020 by kyazuki

[Draco18s]

6 minutes ago, kyazuki said:

java.lang.RuntimeException: Attempted to load class net/minecraft/client/entity/player/ClientPlayerEntity for invalid dist DEDICATED_SERVER

Show your code, but this is probably a case of Reaching Across Sides.

Yep, here:

https://github.com/kyazuki/DietMod/blob/1.16.1-forge/src/main/java/com/github/kyazuki/dietmod/network/CapabilityPacket.java#L29

Your packet exists on both sides. The context contains a reference to the relevant player.

Edited August 7, 2020 by Draco18s

[kyazuki]

I don't understand the packet system fully...

This packet is always sent to client from server.

Can I solve this problem with changing PacketHandler?

Or should I change CapabilityPacket#handle?

[Draco18s]

The packet class must exist on both sides. On the sender, its used to construct the binary data, on the receiver its used to read the binary data.

This is why a Context object is passed to the packet handler.

[kyazuki]

What should I do here?

I know there’s the “OnlyIn” annotation, but I hear it’s not ideal.

[Draco18s]

Do not use only-in.

Get the player from the context.

[kyazuki]

10 minutes ago, Draco18s said:

Get the player from the context.

Context#getSender()?

I want to change ClientPlayer capability.

getSender() returns ServerPlayerEntity...

[poopoodice]

Use the player provided in Minecraft instance.

Edited August 9, 2020 by poopoodice

[kyazuki]

7 minutes ago, poopoodice said:

Use the player provided in Minecraft instance.

Yes, but it causes server crash...

https://github.com/kyazuki/DietMod/blob/37d228d98922fb2d498414dcd2db04f744a2b8f1/src/main/java/com/github/kyazuki/dietmod/network/CapabilityPacket.java#L29

Edited August 9, 2020 by kyazuki

[poopoodice]

Use DistExecutor.

[kyazuki]

It works!

Thanks for the help!

public static void handle(CapabilityPacket pkt, Supplier<NetworkEvent.Context> contextSupplier) {
    NetworkEvent.Context context = contextSupplier.get();
    context.enqueueWork(() -> DistExecutor.safeRunWhenOn(Dist.CLIENT, () -> Handle.handleClient(pkt.playerEntityID, pkt.scale)));
    context.setPacketHandled(true);
  }

  public static class Handle {
    public static DistExecutor.SafeRunnable handleClient(int playerEntityID, float scale) {
      return new DistExecutor.SafeRunnable() {
        @Override
        public void run() {
          PlayerEntity player = (PlayerEntity) Minecraft.getInstance().world.getEntityByID(playerEntityID);
          if (player == null) return;
          player.getCapability(ScaleProvider.SCALE_CAP).orElseThrow(IllegalArgumentException::new).setScale(scale);
        }
      };
    }
  }

[kyazuki]

Is this correct?

Entity player = Minecraft.getInstance().world.getEntityByID(playerEntityID);
if (player == null || !(player instanceof PlayerEntity)) return;

 

Edited August 10, 2020 by kyazuki

[kyazuki]

I see.

Thank you for pointing it out!