Jump to content

[1.16.5] Unknown custom packet identifier


Recommended Posts

When trying to send a package from the Spigot Plugin, this warning appears
I tried to decode it any way or even removed everything, all without success

Unknown custom packet identifier: mod_id:channel_id

Network Init:

public class NetworkHandler {

    public static final String FD_ID = "mod_id";
    public static final String PROTOCOL_VERSION = Integer.toString(1);

    public static void init() {
        SimpleChannel network = NetworkRegistry.newSimpleChannel(
                new ResourceLocation(FD_ID, FDCore.FD_CHANNEL),
                () -> PROTOCOL_VERSION,

        network.registerMessage(0, UIPacket.class, UIPacket::encode, UIPacket::decode, UIPacket::handle);




public class UIPacket {

    private final JsonObject jsonObject;

    public UIPacket(JsonObject jsonObject) {
        this.jsonObject = jsonObject;

    public static void encode(UIPacket packet, PacketBuffer buf) {
        buf.writeUtf(packet.jsonObject.toString(), 262144);

    public static UIPacket decode(PacketBuffer buf) {
        int bytesCount = buf.readableBytes();
        byte[] imageBytes = new byte[bytesCount];
        for (int i = 0; i < bytesCount; ++i)
            imageBytes[i] = buf.readByte();
        // buf.readUtf(262144);

        return new UIPacket(new JsonParser().parse(new String(imageBytes).substring(1)).getAsJsonObject());

    public static void handle(UIPacket packet, Supplier<NetworkEvent.Context> ctx) {
        ctx.get().enqueueWork(() -> {
            JsonObject jsonObject = packet.jsonObject;

            for (UIHandler handler : Handlers.handlersList) {
                if (jsonObject.has(handler.getId())) {



// init
plugin.getServer().getMessenger().registerOutgoingPluginChannel(plugin, CHANNEL);

// sending
player.sendPluginMessage(plugin, CHANNEL, "text".getBytes(StandardCharsets.UTF_8));
Edited by spray
Link to comment
Share on other sites

This topic is now closed to further replies.


  • Create New...

Important Information

By using this site, you agree to our Terms of Use.