Various fixes and improvements for Forge WE 1.13.

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/ForgeAdapter.java

@@ -21,6 +21,7 @@ package com.sk89q.worldedit.forge;
 
 import com.google.common.collect.ImmutableList;
 import com.sk89q.jnbt.CompoundTag;
+import com.sk89q.jnbt.Tag;
 import com.sk89q.worldedit.blocks.BaseItemStack;
 import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.math.Vector3;
@@ -210,11 +211,23 @@ public final class ForgeAdapter {
         if (baseItemStack.getNbtData() != null) {
             forgeCompound = NBTConverter.toNative(baseItemStack.getNbtData());
         }
-        return new ItemStack(adapt(baseItemStack.getType()), baseItemStack.getAmount(), forgeCompound);
+        final ItemStack itemStack = new ItemStack(adapt(baseItemStack.getType()), baseItemStack.getAmount());
+        itemStack.setTag(forgeCompound);
+        return itemStack;
     }
 
     public static BaseItemStack adapt(ItemStack itemStack) {
         CompoundTag tag = NBTConverter.fromNative(itemStack.serializeNBT());
+        if (tag.getValue().isEmpty()) {
+            tag = null;
+        } else {
+            final Tag tagTag = tag.getValue().get("tag");
+            if (tagTag instanceof CompoundTag) {
+                tag = ((CompoundTag) tagTag);
+            } else {
+                tag = null;
+            }
+        }
         return new BaseItemStack(adapt(itemStack.getItem()), tag, itemStack.getCount());
     }
 

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/ForgeBlockCategoryRegistry.java

@@ -0,0 +1,46 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.forge;
+
+import com.sk89q.worldedit.registry.Category;
+import com.sk89q.worldedit.world.block.BlockType;
+import com.sk89q.worldedit.world.registry.BlockCategoryRegistry;
+import net.minecraft.tags.BlockTags;
+import net.minecraft.tags.Tag;
+import net.minecraft.util.ResourceLocation;
+
+import java.util.Collections;
+import java.util.Optional;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+public class ForgeBlockCategoryRegistry implements BlockCategoryRegistry {
+    @Override
+    public Set<BlockType> getCategorisedByName(String category) {
+        return Optional.ofNullable(BlockTags.getCollection().get(new ResourceLocation(category)))
+                .map(Tag::getAllElements).orElse(Collections.emptySet())
+                .stream().map(ForgeAdapter::adapt).collect(Collectors.toSet());
+    }
+
+    @Override
+    public Set<BlockType> getAll(Category<BlockType> category) {
+        return getCategorisedByName(category.getId());
+    }
+}

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/ForgeBlockRegistry.java

@@ -26,6 +26,7 @@ import com.sk89q.worldedit.world.registry.BundledBlockRegistry;
 import net.minecraft.block.Block;
 import net.minecraft.block.material.Material;
 import net.minecraft.state.IProperty;
+import net.minecraftforge.fml.loading.FMLLoader;
 
 import java.util.Collection;
 import java.util.HashMap;
@@ -42,7 +43,7 @@ public class ForgeBlockRegistry extends BundledBlockRegistry {
     @Override
     public String getName(BlockType blockType) {
         Block block = ForgeAdapter.adapt(blockType);
-        if (block != null) {
+        if (block != null && FMLLoader.getDist().isClient()) {
             return block.getNameTextComponent().getFormattedText();
         } else {
             return super.getName(blockType);

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/ForgeDataFixer.java

@@ -212,13 +212,14 @@ class ForgeDataFixer extends DataFixerBuilder implements com.sk89q.worldedit.wor
         INSTANCE = this;
         registerConverters();
         registerInspectors();
+        this.fixer = new WrappedDataFixer(DataFixesManager.getDataFixer());
     }
 
 
     // Called after fixers are built and ready for FIXING
     @Override
     public DataFixer build(final Executor executor) {
-        return this.fixer = new WrappedDataFixer(DataFixesManager.getDataFixer());
+        return fixer;
     }
 
     private class WrappedDataFixer implements DataFixer {

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/ForgeItemCategoryRegistry.java

@@ -0,0 +1,46 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.forge;
+
+import com.sk89q.worldedit.registry.Category;
+import com.sk89q.worldedit.world.item.ItemType;
+import com.sk89q.worldedit.world.registry.ItemCategoryRegistry;
+import net.minecraft.tags.ItemTags;
+import net.minecraft.tags.Tag;
+import net.minecraft.util.ResourceLocation;
+
+import java.util.Collections;
+import java.util.Optional;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+public class ForgeItemCategoryRegistry implements ItemCategoryRegistry {
+    @Override
+    public Set<ItemType> getCategorisedByName(String category) {
+        return Optional.ofNullable(ItemTags.getCollection().get(new ResourceLocation(category)))
+                .map(Tag::getAllElements).orElse(Collections.emptySet())
+                .stream().map(ForgeAdapter::adapt).collect(Collectors.toSet());
+    }
+
+    @Override
+    public Set<ItemType> getAll(Category<ItemType> category) {
+        return getCategorisedByName(category.getId());
+    }
+}

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/ForgeItemRegistry.java

@@ -21,6 +21,11 @@ package com.sk89q.worldedit.forge;
 
 import com.sk89q.worldedit.world.item.ItemType;
 import com.sk89q.worldedit.world.registry.BundledItemRegistry;
+import net.minecraft.client.resources.I18n;
+import net.minecraft.item.Item;
+import net.minecraft.util.ResourceLocation;
+import net.minecraftforge.fml.loading.FMLLoader;
+import net.minecraftforge.registries.RegistryManager;
 
 import javax.annotation.Nullable;
 
@@ -29,6 +34,13 @@ public class ForgeItemRegistry extends BundledItemRegistry {
     @Nullable
     @Override
     public String getName(ItemType itemType) {
-        return super.getName(itemType); // TODO
+        if (FMLLoader.getDist().isClient()) {
+            final Item item = RegistryManager.ACTIVE.getRegistry(Item.class)
+                    .getValue(ResourceLocation.tryCreate(itemType.getId()));
+            if (item != null) {
+                return I18n.format(item.getTranslationKey());
+            }
+        }
+        return super.getName(itemType);
     }
 }

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/ForgePlayer.java

@@ -19,6 +19,7 @@
 
 package com.sk89q.worldedit.forge;
 
+import com.sk89q.jnbt.CompoundTag;
 import com.sk89q.util.StringUtil;
 import com.sk89q.worldedit.blocks.BaseItemStack;
 import com.sk89q.worldedit.entity.BaseEntity;
@@ -33,12 +34,16 @@ import com.sk89q.worldedit.util.HandSide;
 import com.sk89q.worldedit.util.Location;
 import com.sk89q.worldedit.util.formatting.text.Component;
 import com.sk89q.worldedit.util.formatting.text.serializer.gson.GsonComponentSerializer;
+import com.sk89q.worldedit.world.World;
 import com.sk89q.worldedit.world.block.BaseBlock;
 import com.sk89q.worldedit.world.block.BlockStateHolder;
+import com.sk89q.worldedit.world.block.BlockTypes;
 import io.netty.buffer.Unpooled;
+import net.minecraft.block.Block;
 import net.minecraft.entity.player.EntityPlayerMP;
 import net.minecraft.item.ItemStack;
 import net.minecraft.network.PacketBuffer;
+import net.minecraft.network.play.server.SPacketBlockChange;
 import net.minecraft.network.play.server.SPacketCustomPayload;
 import net.minecraft.network.play.server.SPacketUpdateTileEntity;
 import net.minecraft.util.EnumHand;
@@ -48,12 +53,14 @@ import net.minecraft.util.text.ITextComponent;
 import net.minecraft.util.text.TextComponentString;
 import net.minecraft.util.text.TextFormatting;
 
+import java.io.IOException;
 import java.util.UUID;
 
 import javax.annotation.Nullable;
 
 public class ForgePlayer extends AbstractPlayerActor {
 
+    private static final int STRUCTURE_BLOCK_PACKET_ID = 7;
     private final EntityPlayerMP player;
 
     protected ForgePlayer(EntityPlayerMP player) {
@@ -183,21 +190,38 @@ public class ForgePlayer extends AbstractPlayerActor {
 
     @Override
     public <B extends BlockStateHolder<B>> void sendFakeBlock(BlockVector3 pos, B block) {
+        World world = getWorld();
+        if (!(world instanceof ForgeWorld)) {
+            return;
+        }
         BlockPos loc = ForgeAdapter.toBlockPos(pos);
         if (block == null) {
-            // TODO
+            final SPacketBlockChange packetOut = new SPacketBlockChange(((ForgeWorld) world).getWorld(), loc);
-//            player.sendBlockChange(loc, player.getWorld().getBlockAt(loc).getBlockData());
+            player.connection.sendPacket(packetOut);
         } else {
-            // TODO
+            final SPacketBlockChange packetOut = new SPacketBlockChange();
-//            player.sendBlockChange(loc, BukkitAdapter.adapt(block));
+            PacketBuffer buf = new PacketBuffer(Unpooled.buffer());
-            if (block instanceof BaseBlock && ((BaseBlock) block).hasNbtData()) {
+            buf.writeBlockPos(loc);
+            buf.writeVarInt(Block.getStateId(ForgeAdapter.adapt(block.toImmutableState())));
+            try {
+                packetOut.readPacketData(buf);
+            } catch (IOException e) {
+                return;
+            }
+            player.connection.sendPacket(packetOut);
+            if (block instanceof BaseBlock && block.getBlockType().equals(BlockTypes.STRUCTURE_BLOCK)) {
+                final BaseBlock baseBlock = (BaseBlock) block;
+                final CompoundTag nbtData = baseBlock.getNbtData();
+                if (nbtData != null) {
                     player.connection.sendPacket(new SPacketUpdateTileEntity(
-                        new BlockPos(pos.getBlockX(), pos.getBlockY(), pos.getBlockZ()), 7,
+                            new BlockPos(pos.getBlockX(), pos.getBlockY(), pos.getBlockZ()),
-                        NBTConverter.toNative(((BaseBlock) block).getNbtData()))
+                            STRUCTURE_BLOCK_PACKET_ID,
+                            NBTConverter.toNative(nbtData))
                     );
                 }
             }
         }
+    }
 
     @Override
     public SessionKey getSessionKey() {

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/ForgeRegistries.java

@@ -20,8 +20,10 @@
 package com.sk89q.worldedit.forge;
 
 import com.sk89q.worldedit.world.registry.BiomeRegistry;
+import com.sk89q.worldedit.world.registry.BlockCategoryRegistry;
 import com.sk89q.worldedit.world.registry.BlockRegistry;
 import com.sk89q.worldedit.world.registry.BundledRegistries;
+import com.sk89q.worldedit.world.registry.ItemCategoryRegistry;
 import com.sk89q.worldedit.world.registry.ItemRegistry;
 
 /**
@@ -33,6 +35,8 @@ class ForgeRegistries extends BundledRegistries {
     private final BlockRegistry blockRegistry = new ForgeBlockRegistry();
     private final BiomeRegistry biomeRegistry = new ForgeBiomeRegistry();
     private final ItemRegistry itemRegistry = new ForgeItemRegistry();
+    private final BlockCategoryRegistry blockCategoryRegistry = new ForgeBlockCategoryRegistry();
+    private final ItemCategoryRegistry itemCategoryRegistry = new ForgeItemCategoryRegistry();
 
     @Override
     public BlockRegistry getBlockRegistry() {
@@ -49,6 +53,16 @@ class ForgeRegistries extends BundledRegistries {
         return itemRegistry;
     }
 
+    @Override
+    public BlockCategoryRegistry getBlockCategoryRegistry() {
+        return blockCategoryRegistry;
+    }
+
+    @Override
+    public ItemCategoryRegistry getItemCategoryRegistry() {
+        return itemCategoryRegistry;
+    }
+
     /**
      * Get a static instance.
      *

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/ForgeWorld.java

@@ -60,8 +60,11 @@ import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.EnumActionResult;
+import net.minecraft.util.EnumFacing;
+import net.minecraft.util.EnumHand;
 import net.minecraft.util.ResourceLocation;
 import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.RayTraceResult;
 import net.minecraft.world.World;
 import net.minecraft.world.WorldServer;
 import net.minecraft.world.chunk.Chunk;
@@ -243,25 +246,26 @@ public class ForgeWorld extends AbstractWorld {
 
     @Override
     public boolean useItem(BlockVector3 position, BaseItem item, Direction face) {
-        Item nativeItem = ForgeAdapter.adapt(item.getType());
+        ItemStack stack = ForgeAdapter.adapt(new BaseItemStack(item.getType(), item.getNbtData(), 1));
-        ItemStack stack;
-        if (item.getNbtData() == null) {
-            stack = new ItemStack(nativeItem, 1);
-        } else {
-            stack = new ItemStack(nativeItem, 1, NBTConverter.toNative(item.getNbtData()));
-        }
         World world = getWorld();
-        ItemUseContext itemUseContext = new ItemUseContext(
+        final WorldEditFakePlayer fakePlayer = new WorldEditFakePlayer((WorldServer) world);
-                new WorldEditFakePlayer((WorldServer) world),
+        fakePlayer.setHeldItem(EnumHand.MAIN_HAND, stack);
-                stack,
+        fakePlayer.setLocationAndAngles(position.getBlockX(), position.getBlockY(), position.getBlockZ(),
-                ForgeAdapter.toBlockPos(position),
+                (float) face.toVector().toYaw(), (float) face.toVector().toPitch());
-                ForgeAdapter.adapt(face),
+        final BlockPos blockPos = ForgeAdapter.toBlockPos(position);
-                0f,
+        final EnumFacing enumFacing = ForgeAdapter.adapt(face);
-                0f,
+        ItemUseContext itemUseContext = new ItemUseContext(fakePlayer, stack, blockPos, enumFacing, blockPos.getX(), blockPos.getY(), blockPos.getZ());
-                0f
-        );
         EnumActionResult used = stack.onItemUse(itemUseContext);
-        return used != EnumActionResult.FAIL;
+        if (used != EnumActionResult.SUCCESS) {
+            // try activating the block
+            if (getWorld().getBlockState(blockPos).onBlockActivated(world, blockPos, fakePlayer, EnumHand.MAIN_HAND,
+                    enumFacing, blockPos.getX(), blockPos.getY(), blockPos.getZ())) {
+                used = EnumActionResult.SUCCESS;
+            } else {
+                used = stack.getItem().onItemRightClick(world, fakePlayer, EnumHand.MAIN_HAND).getType();
+            }
+        }
+        return used == EnumActionResult.SUCCESS;
     }
 
     @Override

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/ForgeWorldEdit.java

@@ -46,6 +46,7 @@ import net.minecraft.command.CommandSource;
 import net.minecraft.entity.player.EntityPlayerMP;
 import net.minecraft.tags.BlockTags;
 import net.minecraft.tags.ItemTags;
+import net.minecraft.util.EnumHand;
 import net.minecraft.util.ResourceLocation;
 import net.minecraft.world.World;
 import net.minecraftforge.api.distmarker.Dist;
@@ -105,7 +106,6 @@ public class ForgeWorldEdit {
 
         IEventBus modBus = FMLJavaModLoadingContext.get().getModEventBus();
         modBus.addListener(this::init);
-        modBus.addListener(this::load);
 
         MinecraftForge.EVENT_BUS.register(ThreadSafeCache.getInstance());
         MinecraftForge.EVENT_BUS.register(this);
@@ -131,24 +131,6 @@ public class ForgeWorldEdit {
         LOGGER.info("WorldEdit for Forge (version " + getInternalVersion() + ") is loaded");
     }
 
-    private void load(FMLLoadCompleteEvent event) {
-        if (FMLLoader.getDist() == Dist.CLIENT) {
-            // we want to setup platform before we hit the main menu
-            // but this event is async -- so we must delay until the first game loop:
-            Minecraft.getInstance().addScheduledTask(this::setupPlatform);
-        }
-    }
-
-    @SubscribeEvent
-    public void serverAboutToStart(FMLServerAboutToStartEvent event) {
-        if (this.platform != null) {
-            LOGGER.warn("FMLServerStartingEvent occurred when FMLServerStoppingEvent hasn't");
-            WorldEdit.getInstance().getPlatformManager().unregister(platform);
-        }
-
-        setupPlatform();
-    }
-
     private void setupPlatform() {
         this.platform = new ForgePlatform(this);
 
@@ -159,11 +141,6 @@ public class ForgeWorldEdit {
 //        } else {
         this.provider = new ForgePermissionsProvider.VanillaPermissionsProvider(platform);
 //        }
-
-        setupRegistries();
-
-        config = new ForgeConfiguration(this);
-        config.load();
     }
 
     private void setupRegistries() {
@@ -214,6 +191,11 @@ public class ForgeWorldEdit {
 
     @SubscribeEvent
     public void serverStarted(FMLServerStartedEvent event) {
+        setupPlatform();
+        setupRegistries();
+
+        config = new ForgeConfiguration(this);
+        config.load();
         WorldEdit.getInstance().getEventBus().post(new PlatformReadyEvent());
     }
 
@@ -228,7 +210,7 @@ public class ForgeWorldEdit {
 
         if (event.getWorld().isRemote && event instanceof LeftClickEmpty) {
             // catch LCE, pass it to server
-            InternalPacketHandler.HANDLER.sendToServer(new LeftClickAirEventMessage());
+            InternalPacketHandler.getHandler().sendToServer(new LeftClickAirEventMessage());
             return;
         }
         
@@ -239,7 +221,7 @@ public class ForgeWorldEdit {
                 event instanceof PlayerInteractEvent.RightClickBlock
                         && ((PlayerInteractEvent.RightClickBlock) event)
                                 .getUseItem() == Event.Result.DENY;
-        if (isLeftDeny || isRightDeny || event.getEntity().world.isRemote) {
+        if (isLeftDeny || isRightDeny || event.getEntity().world.isRemote || event.getHand() == EnumHand.OFF_HAND) {
             return;
         }
 
@@ -248,10 +230,7 @@ public class ForgeWorldEdit {
         ForgeWorld world = getWorld(event.getEntityPlayer().world);
 
         if (event instanceof PlayerInteractEvent.LeftClickEmpty) {
-            if (we.handleArmSwing(player)) {
+            we.handleArmSwing(player); // this event cannot be canceled
-                // this event cannot be canceled
-                // event.setCanceled(true);
-            }
         } else if (event instanceof PlayerInteractEvent.LeftClickBlock) {
             Location pos = new Location(world, event.getPos().getX(), event.getPos().getY(), event.getPos().getZ());
 

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/WorldEditFakePlayer.java

@@ -33,4 +33,8 @@ public class WorldEditFakePlayer extends FakePlayer {
         super(world, FAKE_GAME_PROFILE);
     }
 
+    @Override
+    public boolean canEat(boolean ignoreHunger) {
+        return true;
+    }
 }

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/net/handler/InternalPacketHandler.java

@@ -19,20 +19,14 @@
 
 package com.sk89q.worldedit.forge.net.handler;
 
-import com.sk89q.worldedit.forge.ForgeWorldEdit;
 import com.sk89q.worldedit.forge.net.packet.LeftClickAirEventMessage;
 import com.sk89q.worldedit.forge.net.packet.LeftClickAirEventMessage.Handler;
-import net.minecraft.util.ResourceLocation;
-import net.minecraftforge.fml.network.NetworkRegistry.ChannelBuilder;
 import net.minecraftforge.fml.network.simple.SimpleChannel;
 
 public final class InternalPacketHandler {
-    private static final String PROTOCOL_VERSION = Integer.toString(1);
+    private static final int PROTOCOL_VERSION = 1;
-    public static SimpleChannel HANDLER = ChannelBuilder
+    private static SimpleChannel HANDLER = PacketHandlerUtil
-            .named(new ResourceLocation(ForgeWorldEdit.MOD_ID, "internal"))
+            .buildLenientHandler("internal", PROTOCOL_VERSION)
-            .clientAcceptedVersions(PROTOCOL_VERSION::equals)
-            .serverAcceptedVersions(PROTOCOL_VERSION::equals)
-            .networkProtocolVersion(() -> PROTOCOL_VERSION)
             .simpleChannel();
 
     private InternalPacketHandler() {
@@ -42,4 +36,8 @@ public final class InternalPacketHandler {
         HANDLER.registerMessage(0, LeftClickAirEventMessage.class,
                 LeftClickAirEventMessage::encode, LeftClickAirEventMessage::decode, Handler::handle);
     }
+
+    public static SimpleChannel getHandler() {
+        return HANDLER;
+    }
 }

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/net/handler/PacketHandlerUtil.java

@@ -0,0 +1,48 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.forge.net.handler;
+
+import com.sk89q.worldedit.forge.ForgeWorldEdit;
+import net.minecraft.util.ResourceLocation;
+import net.minecraftforge.fml.network.NetworkRegistry;
+
+import java.util.function.Predicate;
+
+final class PacketHandlerUtil {
+    private PacketHandlerUtil() {
+    }
+
+    static NetworkRegistry.ChannelBuilder buildLenientHandler(String id, int protocolVersion) {
+        final String verStr = Integer.toString(protocolVersion);
+        final Predicate<String> validator = validateLenient(verStr);
+        return NetworkRegistry.ChannelBuilder
+                .named(new ResourceLocation(ForgeWorldEdit.MOD_ID, id))
+                .clientAcceptedVersions(validator)
+                .serverAcceptedVersions(validator)
+                .networkProtocolVersion(() -> verStr);
+    }
+
+    private static Predicate<String> validateLenient(String protocolVersion) {
+        return remoteVersion ->
+                protocolVersion.equals(remoteVersion)
+                        || NetworkRegistry.ABSENT.equals(remoteVersion)
+                        || NetworkRegistry.ACCEPTVANILLA.equals(remoteVersion);
+    }
+}

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/net/handler/WECUIPacketHandler.java

@@ -29,7 +29,6 @@ import net.minecraft.network.play.server.SPacketCustomPayload;
 import net.minecraft.util.ResourceLocation;
 import net.minecraftforge.fml.network.NetworkEvent.ClientCustomPayloadEvent;
 import net.minecraftforge.fml.network.NetworkEvent.ServerCustomPayloadEvent;
-import net.minecraftforge.fml.network.NetworkRegistry.ChannelBuilder;
 import net.minecraftforge.fml.network.event.EventNetworkChannel;
 
 import java.nio.charset.Charset;
@@ -41,14 +40,12 @@ public final class WECUIPacketHandler {
     }
 
     public static final Charset UTF_8_CHARSET = Charset.forName("UTF-8");
-    private static final String PROTOCOL_VERSION = Integer.toString(1);
+    private static final int PROTOCOL_VERSION = 1;
-    public static EventNetworkChannel HANDLER = ChannelBuilder
+    private static EventNetworkChannel HANDLER = PacketHandlerUtil
-            .named(new ResourceLocation(ForgeWorldEdit.MOD_ID, ForgeWorldEdit.CUI_PLUGIN_CHANNEL))
+            .buildLenientHandler(ForgeWorldEdit.CUI_PLUGIN_CHANNEL, PROTOCOL_VERSION)
-            .clientAcceptedVersions(PROTOCOL_VERSION::equals)
-            .serverAcceptedVersions(PROTOCOL_VERSION::equals)
-            .networkProtocolVersion(() -> PROTOCOL_VERSION)
             .eventNetworkChannel();
 
+    
     public static void init() {
         HANDLER.addListener(WECUIPacketHandler::onPacketData);
         HANDLER.addListener(WECUIPacketHandler::callProcessPacket);