[1.7.10] EntityClientPlayerMP cannot be cast to EntityPlayerMP

gline9 · November 23, 2014

I have created a gui for a block I made that only needs to transfer 1 integer worth of information over to the server and client tile entities. I thought that using IMessage and IMessageHandler would be useful in syncing the two tile entities but when I send the message it calls and index of -1 and won't send...

Here is my code:

Block class:

package com.gavincraft.blocks;

import java.util.Random;

import com.gavincraft.main.GavinCraft;
import com.gavincraft.tileentity.TileEntityAdvancedCatapult;

import net.minecraft.block.Block;
import net.minecraft.block.BlockContainer;
import net.minecraft.block.material.Material;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.tileentity.TileEntity;
import net.minecraft.world.IBlockAccess;
import net.minecraft.world.World;

public class AdvancedCatapult extends BlockContainer {
private boolean activeState = false;
public AdvancedCatapult(boolean active) {
	super(Material.piston);
	this.setStepSound(soundTypePiston);
	this.activeState=active;
}
public boolean canConnectRedstone(IBlockAccess world, int x, int y, int z, int side){
	return true;
}
public void onBlockAdded(World world, int x, int y, int z)
    {
        if (!world.isRemote)
        {
            if (this.activeState && !world.isBlockIndirectlyGettingPowered(x, y, z))
            {
                world.scheduleBlockUpdate(x, y, z, this, this.tickRate(world));
            }
            else if (!this.activeState && world.isBlockIndirectlyGettingPowered(x, y, z))
            {
                world.setBlock(x, y, z, GavinCraft.active_advanced_catapult, 1, 2);
                this.activeState = true;
            }
        }
    }
public void updateTick(World world, int x, int y, int z, Random p_149674_5_)
    {
    	if (!world.isRemote && this.activeState && !world.isBlockIndirectlyGettingPowered(x, y, z))
        {
            world.setBlock(x, y, z, GavinCraft.advanced_catapult, 0, 2);
            this.activeState = false;
            
        }
    	if(!world.isRemote && this.activeState && world.isBlockIndirectlyGettingPowered(x, y, z)){
    		world.setBlock(x, y, z, GavinCraft.active_advanced_catapult, 1, 2);
    		this.activeState = true;
    	}
    	this.setLightLevel(world.getLightBrightness(x, y+1, z));
    }
public void onNeighborBlockChange(World world, int x, int y, int z, Block block)
    {
	if (!world.isRemote)
        {
            if (this.activeState && !world.isBlockIndirectlyGettingPowered(x, y, z))
            {
            	world.scheduleBlockUpdate(x, y, z, this, this.tickRate(world));
            }
            else if (!this.activeState && world.isBlockIndirectlyGettingPowered(x, y, z))
            {
            	world.setBlock(x, y, z, GavinCraft.active_advanced_catapult, 1, 2);
            	this.activeState = true;
            }
        }
    }
@Override
public boolean onBlockActivated(World world, int x, int y, int z, EntityPlayer player, int metadata, float what, float are, float these ){
	TileEntity tileEntity = world.getTileEntity(x, y, z);
	if (player.isSneaking()||tileEntity == null){
		return false;
	}
	player.openGui(GavinCraft.instance, 20, world, x, y, z);
	return true;
}
public int tickRate(World world)
    {
        return activeState?1:2;
    }
@Override
public TileEntity createNewTileEntity(World var1, int var2) {
	return new TileEntityAdvancedCatapult();
}

}

TileEntity class:

package com.gavincraft.tileentity;

import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.nbt.NBTTagCompound;
import net.minecraft.tileentity.TileEntity;

public class TileEntityAdvancedCatapult extends TileEntity {
public int strength = 0;
public void updateEntity(){
	EntityPlayer person = (EntityPlayer) this.worldObj.getClosestPlayer(this.xCoord, this.yCoord, this.zCoord, 2);
	if (person != null && ((int)(Math.abs(person.posX-(person.posX<0?1:0)))) == Math.abs(xCoord) && person.posY -1 == yCoord  && ((int)(Math.abs(person.posZ-(person.posZ<0?1:0)))) == Math.abs(zCoord)){
		if (this.worldObj.getBlock(xCoord, yCoord, zCoord).tickRate(this.worldObj)==1){
			person.velocityChanged=true;
			person.setVelocity(0, strength/10, 0);
		}
	}
}
public void readFromNBT(NBTTagCompound tag){
	super.readFromNBT(tag);
	strength = tag.getInteger("strength");
}
public void writeToNBT(NBTTagCompound tag){
	super.writeToNBT(tag);
	tag.setInteger("strength", strength);
}
}

IMessage class:

package com.gavincraft.packet;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import cpw.mods.fml.common.network.simpleimpl.IMessage;

public class PacketAdvancedCatapult implements IMessage {
public int strength;
public int xPos;
public int yPos;
public int zPos;
public PacketAdvancedCatapult(int var1, int x, int y, int z){
	strength = var1;
	xPos = x;
	yPos = y;
	zPos = z;
}
public PacketAdvancedCatapult(){}
@Override
public void fromBytes(ByteBuf buf) {
	strength = buf.getInt(0);
	xPos = buf.getInt(0);
	yPos = buf.getInt(0);
	zPos = buf.getInt(0);
	System.out.println("message decoded");
}

@Override
public void toBytes(ByteBuf buf) {
	buf.setInt(0, strength);
	buf.setInt(0, xPos);
	buf.setInt(0, yPos);
	buf.setInt(0, zPos);
	System.out.println("message coded");
}

}

IMessageHandler class:

package com.gavincraft.packet.handler;

import com.gavincraft.packet.PacketAdvancedCatapult;
import com.gavincraft.tileentity.TileEntityAdvancedCatapult;

import cpw.mods.fml.common.network.simpleimpl.IMessage;
import cpw.mods.fml.common.network.simpleimpl.IMessageHandler;
import cpw.mods.fml.common.network.simpleimpl.MessageContext;


public class PacketHandlerAdvancedCatapult implements IMessageHandler<PacketAdvancedCatapult, IMessage> {
public PacketHandlerAdvancedCatapult(){}
@Override
public IMessage onMessage(PacketAdvancedCatapult message, MessageContext ctx) {
	System.out.println("message received");
	TileEntityAdvancedCatapult entity = (TileEntityAdvancedCatapult) ctx.getServerHandler().playerEntity.worldObj.getTileEntity(message.xPos, message.yPos, message.zPos);
	System.out.println("entity set");
	entity.strength = message.strength;
	return null;
}

}
[/spoiler]

Gui class:

package com.gavincraft.gui;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;

import org.lwjgl.input.Keyboard;
import org.lwjgl.opengl.GL11;

import com.gavincraft.main.GavinCraft;
import com.gavincraft.packet.PacketAdvancedCatapult;
import com.gavincraft.tileentity.TileEntityAdvancedCatapult;

import net.minecraft.client.gui.GuiButton;
import net.minecraft.client.gui.GuiScreen;
import net.minecraft.client.gui.GuiScreenDemo;
import net.minecraft.client.gui.inventory.GuiContainer;
import net.minecraft.client.renderer.Tessellator;
import net.minecraft.client.resources.I18n;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.entity.player.EntityPlayerMP;
import net.minecraft.entity.player.InventoryPlayer;
import net.minecraft.item.ItemStack;
import net.minecraft.nbt.NBTTagCompound;
import net.minecraft.nbt.NBTTagList;
import net.minecraft.network.PacketBuffer;
import net.minecraft.network.play.client.C17PacketCustomPayload;
import net.minecraft.util.ResourceLocation;
import net.minecraft.world.World;

public class GuiAdvancedCatapult extends GuiScreen {
public static final int GUI_ID = 20;
private static final ResourceLocation resource = new ResourceLocation("textures/gui/demo_background.png");
private int strength;
private ItemStack item;
private NBTTagCompound nbt;
private EntityPlayer player;
private World worldObj;
private int xPos;
private int yPos;
private int zPos;
public GuiAdvancedCatapult(EntityPlayer entityPlayer, ItemStack itemStack, World world, int x, int y, int z){
	worldObj = world;
	xPos = x;
	yPos = y;
	zPos = z;
	item = itemStack;
	player = entityPlayer;
	if (item.hasTagCompound()){
		NBTTagCompound nbt = item.getTagCompound();
		strength = nbt.getInteger("strength");
	}else{
		nbt = new NBTTagCompound();
		strength = 0;
	}
}
public void drawScreen(int par1, int par2, float par3) {
	this.mc.renderEngine.bindTexture(new ResourceLocation("gavincraft:/textures/gui/advancedcatapultgui.png"));
	this.drawDefaultBackground();
	int k = (this.width - 248) / 2 + 10;
        int l = (this.height - 166) / 2 + 8;
        this.fontRendererObj.drawString("Advanced Catapult", k, l, 2039583);
        this.fontRendererObj.drawString(String.valueOf(this.strength), k+100, l+66, 2039583);
        super.drawScreen(par1, par2, par3);
}
public void drawDefaultBackground()
    {
        super.drawDefaultBackground();
        GL11.glColor4f(1.0F, 1.0F, 1.0F, 1.0F);
        this.mc.getTextureManager().bindTexture(resource);
        int i = (this.width - 248) / 2;
        int j = (this.height - 166) / 2;
        this.drawTexturedModalRect(i, j, 0, 0, 248, 166);
    }
public void initGui()
    {
        this.buttonList.clear();
        byte b0 = -16;
        this.buttonList.add(new GuiButton(1, this.width / 2 - 116, this.height / 2 + b0, 40, 20, "+1"));
        this.buttonList.add(new GuiButton(2, this.width / 2 - 71, this.height / 2 + b0, 40, 20, "+10"));
        this.buttonList.add(new GuiButton(3, this.width / 2 + 31, this.height / 2 + b0, 40, 20, "-10"));
        this.buttonList.add(new GuiButton(4, this.width / 2 + 76, this.height / 2 + b0, 40, 20, "-1"));
        this.buttonList.add(new GuiButton(5, this.width / 2 - 116, this.height / 2 + 62 + b0, 100, 20, "Confirm"));
    }
protected void actionPerformed(GuiButton button){
	switch (button.id){
	case 1:{
		this.strength++;
		if (this.strength>100)
			this.strength=100;
		this.updateScreen();
		break;
	}
	case 2:{
		this.strength+=10;
		if (this.strength>100)
			this.strength=100;
		this.updateScreen();
		break;
	}
	case 3:{
		this.strength-=10;
		if (this.strength<0)
			this.strength=0;
		this.updateScreen();
		break;
	}
	case 4:{
		this.strength--;
		if (this.strength<0)
			this.strength=0;
		this.updateScreen();
		break;
	}
	case 5:{
		this.mc.displayGuiScreen((GuiScreen)null);
            this.mc.setIngameFocus();
	}
	}
}
public void onGuiClosed(){
	nbt.setInteger("strength", this.strength);
	if (this.item.hasTagCompound()){
		System.out.println("has tag compound");
            NBTTagCompound nbttagcompound = this.item.getTagCompound();
            nbttagcompound.setInteger("strength", this.strength);
        }else{
            this.item.setTagInfo("strength", this.nbt);
        }
	GavinCraft.channel.sendToServer(new PacketAdvancedCatapult(strength, xPos, yPos, zPos));
    }
}

my common proxy class

package com.gavincraft.main;

import com.gavincraft.gui.GuiAdvancedCatapult;

import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.world.World;
import cpw.mods.fml.common.network.IGuiHandler;

public class CommonProxy implements IGuiHandler {

@Override
public Object getServerGuiElement(int ID, EntityPlayer player, World world, int x, int y, int z) {
	return null;
}

@Override
public Object getClientGuiElement(int ID, EntityPlayer player, World world, int x, int y, int z) {
	if (ID == GuiAdvancedCatapult.GUI_ID){
		return new GuiAdvancedCatapult(player, new ItemStack(Item.getItemFromBlock(world.getBlock(x, y, z)), 1), world, x, y, z);
	}
	return null;
}

}

finally the main class:

package com.gavincraft.main;

import net.minecraft.block.Block;
import net.minecraft.creativetab.CreativeTabs;
import net.minecraft.init.Blocks;
import net.minecraft.init.Items;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;

import com.gavincraft.blocks.AdjustmentCore;
import com.gavincraft.blocks.AdvancedCatapult;
import com.gavincraft.blocks.BigSpring;
import com.gavincraft.blocks.CamoflageCore;
import com.gavincraft.blocks.Casing;
import com.gavincraft.blocks.Catapult;
import com.gavincraft.blocks.Coil;
import com.gavincraft.blocks.Core;
import com.gavincraft.blocks.EnderShard;
import com.gavincraft.blocks.OpenBook;
import com.gavincraft.blocks.ReinforcedCasing;
import com.gavincraft.blocks.SemiSolidFloor;
import com.gavincraft.blocks.ShockAbsorber;
import com.gavincraft.blocks.Spring;
import com.gavincraft.blocks.TeleportCore;
import com.gavincraft.creativeTabs.GavinCraftTab;
import com.gavincraft.tileentity.TileEntityOpenBook;
import com.gavincraft.tileentity.TileEntitySemiSolidFloor;

import cpw.mods.fml.common.Mod;
import cpw.mods.fml.common.Mod.EventHandler;
import cpw.mods.fml.common.Mod.Instance;
import cpw.mods.fml.common.SidedProxy;
import cpw.mods.fml.common.event.FMLInitializationEvent;
import cpw.mods.fml.common.event.FMLPostInitializationEvent;
import cpw.mods.fml.common.event.FMLPreInitializationEvent;
import cpw.mods.fml.common.network.NetworkRegistry;
import cpw.mods.fml.common.network.simpleimpl.SimpleNetworkWrapper;
import cpw.mods.fml.common.registry.GameRegistry;
import cpw.mods.fml.relauncher.Side;

@Mod(modid = GavinCraft.MODID, version = GavinCraft.VERSION)
public class GavinCraft
{
@Instance(GavinCraft.MODID)
    public static GavinCraft instance;
@SidedProxy(clientSide="com.gavincraft.main.ClientProxy", serverSide="com.gavincraft.main.ServerProxy")
public static ServerProxy serverProxy;
public static CreativeTabs gavinCraftTab = new GavinCraftTab(CreativeTabs.getNextID(), "Gavin Craft");
public static SimpleNetworkWrapper channel;

    public static final String MODID = "gavincraft";
    public static final String VERSION = "0.0.0";
    public static Block catapult = new Catapult(false).setCreativeTab(gavinCraftTab).setBlockName("Catapult");
    public static Block active_catapult = new Catapult(true).setBlockName("Catapult");
    public static Item spring = new Spring().setCreativeTab(gavinCraftTab).setUnlocalizedName("Spring").setTextureName("gavincraft:spring");
    public static Item coil = new Coil().setCreativeTab(gavinCraftTab).setUnlocalizedName("Coil").setTextureName("gavincraft:coil");
    public static Block casing = new Casing().setCreativeTab(gavinCraftTab).setBlockName("Casing").setBlockTextureName("gavincraft:casing");
    public static Item big_spring = new BigSpring().setUnlocalizedName("Big_Spring").setCreativeTab(gavinCraftTab).setTextureName("gavincraft:big spring");
    public static Block reinforced_casing = new ReinforcedCasing().setBlockName("Reinforced_Casing").setCreativeTab(gavinCraftTab).setBlockTextureName("gavincraft:reinforced casing");
    public static Block shock_absorber = new ShockAbsorber().setBlockName("Shock_Absorber").setCreativeTab(gavinCraftTab).setBlockTextureName("gavincraft:shockabsorber");
    public static Item teleport_core = new TeleportCore().setUnlocalizedName("Teleport_Core").setCreativeTab(gavinCraftTab).setTextureName("gavincraft:teleport core");
    public static Block open_book = new OpenBook().setBlockName("Open_Book").setCreativeTab(gavinCraftTab);
    public static Block semi_solid_floor = new SemiSolidFloor().setBlockName("Semi-Solid_Floor").setCreativeTab(gavinCraftTab).setBlockTextureName("gavincraft:semisolidfloor");
    public static Item ender_shard = new EnderShard().setUnlocalizedName("Ender_Shard").setCreativeTab(gavinCraftTab).setTextureName("gavincraft:ender shard");
    public static Item core = new Core().setUnlocalizedName("Core").setCreativeTab(gavinCraftTab).setTextureName("gavincraft:core");
    public static Item camoflage_core = new CamoflageCore().setUnlocalizedName("Camoflage_Core").setCreativeTab(gavinCraftTab).setTextureName("gavincraft:camoflage core");
    public static Block advanced_catapult = new AdvancedCatapult(false).setBlockName("Advanced_Catapult").setCreativeTab(gavinCraftTab);
    public static Block active_advanced_catapult = new AdvancedCatapult(true).setBlockName("Advanced_Catapult");
    public static Item adjustment_core = new AdjustmentCore().setUnlocalizedName("Adjustment_Core").setCreativeTab(gavinCraftTab);
    
    @EventHandler
    public void preInit(FMLPreInitializationEvent event){
    	serverProxy.registerRenderThings();
    	channel = NetworkRegistry.INSTANCE.newSimpleChannel(GavinCraft.MODID);
    	channel.registerMessage(com.gavincraft.packet.handler.PacketHandlerAdvancedCatapult.class, com.gavincraft.packet.PacketAdvancedCatapult.class, 0, Side.SERVER);
    	
    	GameRegistry.registerBlock(catapult, "catapult");
    	GameRegistry.registerItem(spring, "Spring");
    	GameRegistry.registerItem(coil, "Coil");
    	GameRegistry.registerBlock(casing, "Casing");
    	GameRegistry.registerItem(big_spring, "Big_Spring");
    	GameRegistry.registerBlock(reinforced_casing, "Reinforced_Casing");
    	GameRegistry.registerBlock(shock_absorber, "Shock_Absorber");
    	GameRegistry.registerItem(teleport_core, "Teleport_Core");
    	GameRegistry.registerBlock(open_book, "Open Book");
    	GameRegistry.registerBlock(semi_solid_floor, "Semi-Solid_Floor");
    	GameRegistry.registerTileEntity(TileEntityOpenBook.class, "Open_Book");
    	GameRegistry.registerBlock(active_catapult, "Active_Catapult");
    	GameRegistry.registerItem(ender_shard, "Ender_Shard");
    	GameRegistry.registerItem(core, "Core");
    	GameRegistry.registerItem(camoflage_core, "Camoflage_Core");
    	GameRegistry.registerBlock(advanced_catapult, "Advanced_Catapult");
    	GameRegistry.registerBlock(active_advanced_catapult, "Active_Advanced_Catapult");
    	GameRegistry.registerItem(adjustment_core, "Adjustment_Core");
    	
    	
    	GameRegistry.addRecipe(new ItemStack(Blocks.vine), new Object[]{
    		"xxx",
    		"xyx",
    		"xxx",
    		'x', Items.wheat, 'y', Blocks.dirt});
    	GameRegistry.addRecipe(new ItemStack(GavinCraft.coil, 9), new Object[]{
    		"xxx",
    		"x x",
    		"xxx",
    		'x', Items.iron_ingot});
    	GameRegistry.addRecipe(new ItemStack(GavinCraft.spring), new Object[]{
    		"xxx",
    		'x', GavinCraft.coil});
    	GameRegistry.addRecipe(new ItemStack(GavinCraft.casing, 2), new Object[]{
    		"xxx",
    		"xyx",
    		"xxx",
    		'x', Blocks.stone, 'y', Items.iron_ingot});
    	GameRegistry.addRecipe(new ItemStack(GavinCraft.catapult), new Object[]{
    		"xxx",
    		"yzy",
    		"ywy",
    		'x', Blocks.piston, 'y', GavinCraft.casing, 'z', GavinCraft.spring, 'w', Items.redstone});
    	GameRegistry.addRecipe(new ItemStack(GavinCraft.big_spring, 2), new Object[]{
    		"xxx",
    		"yyy",
    		"xxx",
    		'x', Items.gold_ingot,'y', GavinCraft.spring});
    	GameRegistry.addRecipe(new ItemStack(GavinCraft.reinforced_casing, 2), new Object[]{
    		"yxy",
    		"x x",
    		"yxy",
    		'x', GavinCraft.casing, 'y', Blocks.obsidian});
    	GameRegistry.addRecipe(new ItemStack(GavinCraft.shock_absorber), new Object[]{
    		"xxx",
    		"yyy",
    		"xxx",
    		'x', Blocks.wool, 'y', GavinCraft.spring});
    	GameRegistry.addRecipe(new ItemStack(GavinCraft.teleport_core, 1), new Object[]{
    		"xyx",
    		"yzy",
    		"xyx",
    		'x', Items.glowstone_dust, 'y', GavinCraft.casing, 'z', GavinCraft.core});
    	GameRegistry.addRecipe(new ItemStack(GavinCraft.semi_solid_floor, 1), new Object[]{
    		"xwx",
    		"zuz",
    		"xyx",
    		'x', GavinCraft.casing, 'y', GavinCraft.teleport_core, 'z', Items.iron_ingot, 'w', GavinCraft.shock_absorber, 'u', GavinCraft.camoflage_core});
    	GameRegistry.addRecipe(new ItemStack(GavinCraft.ender_shard, , new Object[]{
    		"x",
    		'x', Items.ender_pearl
    	});
    	GameRegistry.addRecipe(new ItemStack(GavinCraft.core, 1), new Object[]{
    		"xyx",
    		"yzy",
    		"xyx",
    		'x', Items.redstone, 'y', GavinCraft.ender_shard, 'z', GavinCraft.casing
    	});
    	GameRegistry.addRecipe(new ItemStack(GavinCraft.camoflage_core, 1), new Object[]{
    		" x ",
    		"yzw",
    		" u ",
    		'x',new ItemStack(Items.dye, 1, 1), 'y', new ItemStack(Items.dye, 1, 2), 'z', GavinCraft.core, 'w', new ItemStack(Items.dye, 1, 4), 'u', new ItemStack(Items.dye, 1, 0)
    	});
    	GameRegistry.addRecipe(new ItemStack(GavinCraft.adjustment_core, 1), new Object[]{
    		"xyx",
    		"yzy",
    		"xyx",
    		'x', GavinCraft.coil, 'y', GavinCraft.spring, 'z', GavinCraft.core
    	});
    	GameRegistry.addRecipe(new ItemStack(GavinCraft.advanced_catapult, 1), new Object[]{
    		" x ",
    		"yzy",
    		"ywy",
    		'x', GavinCraft.catapult, 'y', GavinCraft.reinforced_casing, 'z', GavinCraft.big_spring, 'w', GavinCraft.adjustment_core
    	});
    }
    
    @EventHandler
    public void load(FMLInitializationEvent event){
    	NetworkRegistry.INSTANCE.registerGuiHandler(instance, new CommonProxy());
    	GameRegistry.registerTileEntity(com.gavincraft.tileentity.TileEntitySemiSolidFloor.class, "Semi_Solid_Floor_Tile_Entity");
    	GameRegistry.registerTileEntity(com.gavincraft.tileentity.TileEntityCatapult.class, "Catapult_Tile_Entity");
    	GameRegistry.registerTileEntity(com.gavincraft.tileentity.TileEntityAdvancedCatapult.class, "Advanced_Catapult_Tile_Entity");
    }
    @EventHandler
    public void postinit(FMLPostInitializationEvent event){
    }
}

and here is the error log that I am getting.

io.netty.handler.codec.DecoderException: java.lang.NullPointerException: Undefined message for discriminator -1 in channel gavincraft

at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:99) ~[MessageToMessageDecoder.class:?]

at io.netty.handler.codec.MessageToMessageCodec.channelRead(MessageToMessageCodec.java:111) ~[MessageToMessageCodec.class:?]

at io.netty.channel.DefaultChannelHandlerContext.invokeChannelRead(DefaultChannelHandlerContext.java:337) [DefaultChannelHandlerContext.class:?]

at io.netty.channel.DefaultChannelHandlerContext.fireChannelRead(DefaultChannelHandlerContext.java:323) [DefaultChannelHandlerContext.class:?]

at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:785) [DefaultChannelPipeline.class:?]

at io.netty.channel.embedded.EmbeddedChannel.writeInbound(EmbeddedChannel.java:169) [EmbeddedChannel.class:?]

at cpw.mods.fml.common.network.internal.FMLProxyPacket.processPacket(FMLProxyPacket.java:86) [FMLProxyPacket.class:?]

at net.minecraft.network.NetworkManager.processReceivedPackets(NetworkManager.java:241) [NetworkManager.class:?]

at net.minecraft.network.NetworkSystem.networkTick(NetworkSystem.java:182) [NetworkSystem.class:?]

at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:726) [MinecraftServer.class:?]

at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:614) [MinecraftServer.class:?]

at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:118) [integratedServer.class:?]

at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:485) [MinecraftServer.class:?]

at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:752) [MinecraftServer$2.class:?]

Caused by: java.lang.NullPointerException: Undefined message for discriminator -1 in channel gavincraft

at cpw.mods.fml.common.network.FMLIndexedMessageToMessageCodec.decode(FMLIndexedMessageToMessageCodec.java:73) ~[FMLIndexedMessageToMessageCodec.class:?]

at cpw.mods.fml.common.network.FMLIndexedMessageToMessageCodec.decode(FMLIndexedMessageToMessageCodec.java:17) ~[FMLIndexedMessageToMessageCodec.class:?]

at io.netty.handler.codec.MessageToMessageCodec$2.decode(MessageToMessageCodec.java:81) ~[MessageToMessageCodec$2.class:?]

at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:89) ~[MessageToMessageDecoder.class:?]

... 13 more

[18:11:10] [server thread/ERROR] [FML]: SimpleChannelHandlerWrapper exception