2 files changed, 32 insertions, 3 deletions
diff --git a/src/main/java/gregtech/api/GregTech_API.java b/src/main/java/gregtech/api/GregTech_API.java
index 223d967895..68d1afdebd 100644
--- a/src/main/java/gregtech/api/GregTech_API.java
+++ b/src/main/java/gregtech/api/GregTech_API.java
@@ -12,6 +12,8 @@ import java.util.function.IntFunction;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
+import javax.annotation.Nonnull;
+
 import net.minecraft.block.Block;
 import net.minecraft.client.renderer.texture.IIconRegister;
 import net.minecraft.creativetab.CreativeTabs;
@@ -60,6 +62,7 @@ import gregtech.api.util.GT_ModHandler;
 import gregtech.api.util.GT_OreDictUnificator;
 import gregtech.api.util.GT_Utility;
 import gregtech.api.world.GT_Worldgen;
+import gregtech.common.GT_DummyWorld;
 import gregtech.common.items.GT_IntegratedCircuit_Item;
 
 /**
@@ -293,9 +296,33 @@ public class GregTech_API {
     @SuppressWarnings("unchecked")
     private static final IntFunction<TileEntity>[] teCreators = new IntFunction[16];
 
+    private static final Set<Class<?>> dummyWorlds = new HashSet<>();
+
     static {
         sItemStackMappings.add(sCovers);
         sItemStackMappings.add(sCoverBehaviors);
+
+        dummyWorlds.add(GT_DummyWorld.class);
+        tryAddDummyWorld("blockrenderer6343.client.world.DummyWorld");
+    }
+
+    private static void tryAddDummyWorld(String className) {
+        ClassLoader cl = GregTech_API.class.getClassLoader();
+        Class<?> clazz;
+        try {
+            clazz = Class.forName(className, false, cl);
+        } catch (ReflectiveOperationException ex) {
+            return;
+        }
+        dummyWorlds.add(clazz);
+    }
+
+    public static void addDummyWorld(Class<?> clazz) {
+        dummyWorlds.add(clazz);
+    }
+
+    public static boolean isDummyWorld(@Nonnull World w) {
+        return dummyWorlds.contains(w.getClass());
     }
 
     /**
@@ -337,7 +364,7 @@ public class GregTech_API {
      * @param aZ     is the Z-Coord of the update causing Block
      */
     public static boolean causeMachineUpdate(World aWorld, int aX, int aY, int aZ) {
-        if (aWorld != null && !aWorld.isRemote) { // World might be null during World-gen
+        if (aWorld != null && !aWorld.isRemote && !isDummyWorld(aWorld)) { // World might be null during World-gen
             GT_Runnable_MachineBlockUpdate.setMachineUpdateValues(aWorld, new ChunkCoordinates(aX, aY, aZ));
             return true;
         }
@@ -346,7 +373,7 @@ public class GregTech_API {
 
     @SuppressWarnings("UnusedReturnValue") // Retains API method signature
     public static boolean causeCableUpdate(World aWorld, int aX, int aY, int aZ) {
-        if (aWorld == null || aWorld.isRemote) {
+        if (aWorld == null || aWorld.isRemote || isDummyWorld(aWorld)) {
             return false;
         } // World might be null during World-gen
         GT_Runnable_Cable_Update.setCableUpdateValues(aWorld, new ChunkCoordinates(aX, aY, aZ));
diff --git a/src/main/java/gregtech/api/metatileentity/implementations/GT_MetaTileEntity_EnhancedMultiBlockBase.java b/src/main/java/gregtech/api/metatileentity/implementations/GT_MetaTileEntity_EnhancedMultiBlockBase.java
index 0b1827bcdb..e5cf3d5cc4 100644
--- a/src/main/java/gregtech/api/metatileentity/implementations/GT_MetaTileEntity_EnhancedMultiBlockBase.java
+++ b/src/main/java/gregtech/api/metatileentity/implementations/GT_MetaTileEntity_EnhancedMultiBlockBase.java
@@ -19,6 +19,7 @@ import com.gtnewhorizon.structurelib.structure.IStructureDefinition;
 import com.gtnewhorizon.structurelib.structure.ISurvivalBuildEnvironment;
 
 import cpw.mods.fml.common.network.NetworkRegistry;
+import gregtech.api.GregTech_API;
 import gregtech.api.interfaces.tileentity.IGregTechTileEntity;
 import gregtech.api.util.GT_Multiblock_Tooltip_Builder;
 
@@ -58,7 +59,8 @@ public abstract class GT_MetaTileEntity_EnhancedMultiBlockBase<T extends GT_Meta
             mMachine = false;
             mUpdated = false;
             mUpdate = 100;
-            if (getBaseMetaTileEntity().isServerSide()) {
+            if (getBaseMetaTileEntity().isServerSide()
+                    && !GregTech_API.isDummyWorld(getBaseMetaTileEntity().getWorld())) {
                 StructureLibAPI.sendAlignment(
                         (IAlignmentProvider) base,
                         new NetworkRegistry.TargetPoint(