R4L

Found the solution! Instead of using PlayerEvent.Clone to sync capabilities with a client use EntityJoinWorldEvent! That's how CapabilitySync class should look like: public class CapabilitySync { @SubscribeEvent public void EntityJoinWorldEvent(EntityJoinWorldEvent event) { Entity entity = event.getEntity(); if (entity.world.isRemote || !(entity instanceof EntityPlayerMP)) return; EntityPlayer player = (EntityPlayer) entity; NetworkHandler.channel.sendTo(new ServerToClient(player), (EntityPlayerMP) player); } @SubscribeEvent public void onPlayerClone(PlayerEvent.Clone event) { EntityPlayer player = event.getEntityPlayer(); IFolder folder = player.getCapability(FolderProvider.FOLDER_CAP, null); IFolder oldfolder = event.getOriginal().getCapability(FolderProvider.FOLDER_CAP, null); folder.setFolders(oldfolder.getFolders()); } } Here is a full code if you need one! https://github.com/R4L34/capabilitynetworking

Remove Just Leveling! It tries to work with capability that equals to null.

I am writing a code that stores String List in a player capability. And I need to sync it to client so I could access it via Minecraft.getMinecraft.player. I use messages for that and everything works fine until I work with the PlayerClone event. According to the logs it should work just fine but for some reason it just doesn't. You need to reconnect to the world to resync everything (messages do work when I use it in PlayerLoggedInEvent). Here is my code: CapabilitySync.java public class CapabilitySync { @SubscribeEvent public void onPlayerLogsIn(PlayerLoggedInEvent event) { EntityPlayer player = event.player; //That thing works just fine NetworkHandler.channel.sendTo(new ServerToClient(player), (EntityPlayerMP) player); } @SubscribeEvent public void onPlayerClone(PlayerEvent.Clone event) { EntityPlayer player = event.getEntityPlayer(); IFolder folder = player.getCapability(FolderProvider.FOLDER_CAP, null); IFolder oldfolder = event.getOriginal().getCapability(FolderProvider.FOLDER_CAP, null); folder.setFolders(oldfolder.getFolders()); // This part doesn't work NetworkHandler.channel.sendTo(new ServerToClient(player), (EntityPlayerMP) player); } } NetworkHandler.java public class NetworkHandler { public static SimpleNetworkWrapper channel = NetworkRegistry.INSTANCE.newSimpleChannel(Reference.MODID); public static void init() { channel.registerMessage(ClientToServer.Handler.class, ClientToServer.class, 0, Side.SERVER); channel.registerMessage(ServerToClient.Handler.class, ServerToClient.class, 1, Side.CLIENT); } public static IThreadListener getThreadListener(MessageContext ctx) { return ctx.side == Side.SERVER ? (WorldServer) ctx.getServerHandler().player.world : getClientThreadListener(); } @SideOnly(Side.CLIENT) public static IThreadListener getClientThreadListener() { return Minecraft.getMinecraft(); } } ClientToServer / ServerToClient messages public class ClientToServer implements IMessage { private List<String> folders; private int folders_count; public ClientToServer () {} public ClientToServer (IFolder folder) { this.folders = folder.getFolders(); this.folders_count = folder.size(); } @Override public void fromBytes(ByteBuf buf) { folders = new ArrayList<>(); folders_count = buf.readInt(); for (int i = 0; i < folders_count; i++) { folders.add(ByteBufUtils.readUTF8String(buf)); } } @Override public void toBytes(ByteBuf buf) { buf.writeInt(folders_count); for (int i = 0; i < folders_count; i++) { ByteBufUtils.writeUTF8String(buf, folders.get(i)); } } public List<String> getFolders (){ return this.folders; } public static class Handler implements IMessageHandler<ClientToServer, IMessage> { @Override public IMessage onMessage(ClientToServer message, MessageContext ctx) { EntityPlayerMP serverPlayer = ctx.getServerHandler().player; NetworkHandler.getThreadListener(ctx).addScheduledTask(() -> { IFolder old_folders = serverPlayer.getCapability(FolderProvider.FOLDER_CAP, null); List<String> new_folders = message.getFolders(); old_folders.setFolders(new_folders); }); return null; } } } public class ServerToClient implements IMessage { private List<String> folders; private int folders_count; public ServerToClient() {} public ServerToClient(EntityPlayer server_player) { this.folders = server_player.getCapability(FolderProvider.FOLDER_CAP, null).getFolders(); this.folders_count = folders.size(); } @Override public void fromBytes(ByteBuf buf) { folders = new ArrayList<>(); folders_count = buf.readInt(); for (int i = 0; i < folders_count; i++) { folders.add(ByteBufUtils.readUTF8String(buf)); } } @Override public void toBytes(ByteBuf buf) { buf.writeInt(folders_count); for (int i = 0; i < folders_count; i++) { ByteBufUtils.writeUTF8String(buf, folders.get(i)); } } public List<String> getFolders (){ return this.folders; } public static class Handler implements IMessageHandler<ServerToClient, IMessage> { @Override public IMessage onMessage(ServerToClient message, MessageContext ctx) { NetworkHandler.getThreadListener(ctx).addScheduledTask(() -> { Minecraft mc = Minecraft.getMinecraft(); IFolder old_folders = mc.player.getCapability(FolderProvider.FOLDER_CAP, null); List<String> new_folders = message.getFolders(); old_folders.setFolders(new_folders); }); return null; } } ClientProxy.java (where I access the capability through a client player) public class ClientProxy extends CommonProxy { @SubscribeEvent public void onKeyInput(KeyInputEvent event) { if (Keybinds.KEY_u.isPressed()) { EntityPlayer playerSP = Minecraft.getMinecraft().player; IFolder folder = playerSP.getCapability(FolderProvider.FOLDER_CAP, null); folder.add("UUUUU"); NetworkHandler.channel.sendToServer(new ClientToServer(folder)); } else if (Keybinds.KEY_i.isPressed()) { EntityPlayer playerSP = Minecraft.getMinecraft().player; IFolder folder = playerSP.getCapability(FolderProvider.FOLDER_CAP, null); for (String f : folder.getFolders()) { String message = f; playerSP.sendMessage(new TextComponentString(message)); } }else if (Keybinds.KEY_o.isPressed()) { EntityPlayer playerSP = Minecraft.getMinecraft().player; IFolder folder = playerSP.getCapability(FolderProvider.FOLDER_CAP, null); Minecraft.getMinecraft().displayGuiScreen(new DefaultGUI(folder)); } } }