Few fixes for the Forge version.

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

@@ -187,8 +187,9 @@ public <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B
 
     @Override
     public boolean notifyAndLightBlock(BlockVector3 position, BlockState previousType) throws WorldEditException {
-        // TODO Implement
-        return false;
+        BlockPos pos = new BlockPos(position.getX(), position.getY(), position.getZ());
+        getWorld().notifyBlockUpdate(pos, ForgeAdapter.adapt(previousType), getWorld().getBlockState(pos), 1 | 2);
+        return true;
     }
 
     @Override

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

@@ -31,6 +31,9 @@
 import com.sk89q.worldedit.forge.net.handler.InternalPacketHandler;
 import com.sk89q.worldedit.forge.net.handler.WECUIPacketHandler;
 import com.sk89q.worldedit.forge.net.packet.LeftClickAirEventMessage;
+import com.sk89q.worldedit.forge.proxy.ClientProxy;
+import com.sk89q.worldedit.forge.proxy.CommonProxy;
+import com.sk89q.worldedit.forge.proxy.ServerProxy;
 import com.sk89q.worldedit.util.Location;
 import com.sk89q.worldedit.world.biome.BiomeType;
 import com.sk89q.worldedit.world.block.BlockCategory;
@@ -89,7 +92,7 @@ public class ForgeWorldEdit {
 
     public static ForgeWorldEdit inst;
 
-    public static CommonProxy proxy = DistExecutor.runForDist(() -> ClientProxy::new, () -> CommonProxy::new);
+    public static CommonProxy proxy = DistExecutor.runForDist(() -> ClientProxy::new, () -> ServerProxy::new);
 
     private ForgePlatform platform;
     private ForgeConfiguration config;

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

@@ -41,7 +41,7 @@ public void onKey(KeyInputEvent evt) {
         if (mc.player != null && mc.world != null && mainKey.isPressed()) {
             mc.displayGuiScreen(new GuiReferenceCard());
             // TODO Seems GuiHandlers don't work on client right now
-//            NetworkHooks.openGui(mc.player, new ResourceLocationInteractionObject(CommonProxy.REFERENCE_GUI));
+//            NetworkHooks.openGui(mc.player, new ResourceLocationInteractionObject(ServerProxy.REFERENCE_GUI));
         }
     }
 

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/gui/GuiReferenceCard.java

@@ -23,8 +23,11 @@
 import net.minecraft.client.gui.GuiButton;
 import net.minecraft.client.gui.GuiScreen;
 import net.minecraft.util.ResourceLocation;
+import net.minecraftforge.api.distmarker.Dist;
+import net.minecraftforge.api.distmarker.OnlyIn;
 import org.lwjgl.opengl.GL11;
 
+@OnlyIn(Dist.CLIENT)
 public class GuiReferenceCard extends GuiScreen {
 
     private GuiButton closeButton;

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/ClientProxy.java → worldedit-forge/src/main/java/com/sk89q/worldedit/forge/proxy/ClientProxy.java

@@ -17,15 +17,18 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-package com.sk89q.worldedit.forge;
+package com.sk89q.worldedit.forge.proxy;
 
+import com.sk89q.worldedit.forge.KeyHandler;
+import net.minecraftforge.api.distmarker.Dist;
+import net.minecraftforge.api.distmarker.OnlyIn;
 import net.minecraftforge.common.MinecraftForge;
 
-public class ClientProxy extends CommonProxy {
+@OnlyIn(Dist.CLIENT)
+public class ClientProxy implements CommonProxy {
 
     @Override
     public void registerHandlers() {
-        super.registerHandlers();
         MinecraftForge.EVENT_BUS.register(new KeyHandler());
     }
 

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/proxy/CommonProxy.java

@@ -0,0 +1,25 @@
+/*
+ * 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.proxy;
+
+public interface CommonProxy {
+
+    void registerHandlers();
+}

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/CommonProxy.java → worldedit-forge/src/main/java/com/sk89q/worldedit/forge/proxy/ServerProxy.java

@@ -17,24 +17,24 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-package com.sk89q.worldedit.forge;
+package com.sk89q.worldedit.forge.proxy;
 
-import com.sk89q.worldedit.forge.gui.GuiReferenceCard;
-import net.minecraft.util.ResourceLocation;
-import net.minecraftforge.fml.ExtensionPoint;
-import net.minecraftforge.fml.ModLoadingContext;
+import net.minecraftforge.api.distmarker.Dist;
+import net.minecraftforge.api.distmarker.OnlyIn;
 
-public class CommonProxy {
+@OnlyIn(Dist.DEDICATED_SERVER)
+public class ServerProxy implements CommonProxy {
 
-    public static ResourceLocation REFERENCE_GUI = new ResourceLocation("worldedit", "resource_gui");
+//    public static ResourceLocation REFERENCE_GUI = new ResourceLocation("worldedit", "resource_gui");
 
+    @Override
     public void registerHandlers() {
-        ModLoadingContext.get().registerExtensionPoint(ExtensionPoint.GUIFACTORY, () -> openContainer -> {
-            if (openContainer.getId().equals(REFERENCE_GUI)) {
-                return new GuiReferenceCard();
-            }
-            return null;
-        });
+//        ModLoadingContext.get().registerExtensionPoint(ExtensionPoint.GUIFACTORY, () -> openContainer -> {
+//            if (openContainer.getId().equals(REFERENCE_GUI)) {
+//                return new GuiReferenceCard();
+//            }
+//            return null;
+//        });
     }
 
 }