diff --git a/pom.xml b/pom.xml
index 8d63e8bb0..6efe8b389 100644
--- a/pom.xml
+++ b/pom.xml
@@ -235,6 +235,12 @@
             <version>${spigot.version}</version>
             <scope>provided</scope>
         </dependency>
+        <dependency>
+             <groupId>org.spigotmc.....</groupId>
+             <artifactId>spigot</artifactId>
+             <version>1.21-R0.1-SNAPSHOT</version>
+             <scope>provided</scope>
+        </dependency>
         <dependency>
              <groupId>org.spigotmc....</groupId>
              <artifactId>spigot</artifactId>
diff --git a/src/main/java/world/bentobox/bentobox/commands/BentoBoxMigrateCommand.java b/src/main/java/world/bentobox/bentobox/commands/BentoBoxMigrateCommand.java
index b4b763270..0face2d24 100644
--- a/src/main/java/world/bentobox/bentobox/commands/BentoBoxMigrateCommand.java
+++ b/src/main/java/world/bentobox/bentobox/commands/BentoBoxMigrateCommand.java
@@ -1,8 +1,13 @@
 package world.bentobox.bentobox.commands;
 
+import java.util.LinkedList;
 import java.util.List;
+import java.util.Queue;
 import java.util.Set;
 
+import org.bukkit.Bukkit;
+import org.bukkit.scheduler.BukkitTask;
+
 import world.bentobox.bentobox.BentoBox;
 import world.bentobox.bentobox.api.commands.CompositeCommand;
 import world.bentobox.bentobox.api.commands.ConfirmableCommand;
@@ -20,6 +25,8 @@ import world.bentobox.bentobox.database.objects.DataObject;
 public class BentoBoxMigrateCommand extends ConfirmableCommand {
 
     private static final String MIGRATED = "commands.bentobox.migrate.migrated";
+    private Queue<Class<? extends DataObject>> classQueue;
+    private BukkitTask task;
 
     /**
      * Reloads settings, addons and localization command
@@ -41,11 +48,21 @@ public class BentoBoxMigrateCommand extends ConfirmableCommand {
             user.sendMessage("commands.bentobox.migrate.addons");
             Set<Class<? extends DataObject>> classSet = getPlugin().getAddonsManager().getDataObjects();
             classSet.addAll(Database.getDataobjects());
-            classSet.forEach(t -> {
-                user.sendMessage("commands.bentobox.migrate.class", TextVariables.DESCRIPTION, BentoBox.getInstance().getSettings().getDatabasePrefix() + t.getCanonicalName());
-                new Database<>(getPlugin(), t).loadObjects();
-                user.sendMessage(MIGRATED);
-            });
+            // Put classSet into classQueue
+            classQueue = new LinkedList<>(classSet);
+            // Start a scheduler to step through these in a reasonable time
+            task = Bukkit.getScheduler().runTaskTimer(getPlugin(), () -> {
+                Class<? extends DataObject> t = classQueue.poll();
+                if (t != null) {
+                    user.sendMessage("commands.bentobox.migrate.class", TextVariables.DESCRIPTION,
+                            BentoBox.getInstance().getSettings().getDatabasePrefix() + t.getCanonicalName());
+                    new Database<>(getPlugin(), t).loadObjects();
+                    user.sendMessage(MIGRATED);
+                } else {
+                    user.sendMessage("commands.bentobox.migrate.completed");
+                    task.cancel();
+                }
+            }, 0, 20L);
         });
         return true;
     }
diff --git a/src/main/java/world/bentobox/bentobox/database/transition/TransitionDatabaseHandler.java b/src/main/java/world/bentobox/bentobox/database/transition/TransitionDatabaseHandler.java
index c1402be8a..966be709c 100644
--- a/src/main/java/world/bentobox/bentobox/database/transition/TransitionDatabaseHandler.java
+++ b/src/main/java/world/bentobox/bentobox/database/transition/TransitionDatabaseHandler.java
@@ -44,8 +44,16 @@ public class TransitionDatabaseHandler<T> extends AbstractDatabaseHandler<T> {
         List<T> listTo = toHandler.loadObjects();
         // If source database has objects, then delete and save them in the destination database
         for (T object : listFrom) {
-            toHandler.saveObject(object);
-            fromHandler.deleteObject(object);
+            toHandler.saveObject(object).thenAccept(b -> {
+                // Only delete if save was successful
+                if (b) {
+                    try {
+                        fromHandler.deleteObject(object);
+                    } catch (IllegalAccessException | InvocationTargetException | IntrospectionException e) {
+                        plugin.logStacktrace(e);
+                    }
+                }
+            });
         }
         // Merge results
         listTo.addAll(listFrom);
diff --git a/src/main/java/world/bentobox/bentobox/nms/v1_21_R0_1_SNAPSHOT/PasteHandlerImpl.java b/src/main/java/world/bentobox/bentobox/nms/v1_21_R0_1_SNAPSHOT/PasteHandlerImpl.java
new file mode 100644
index 000000000..ece376eb2
--- /dev/null
+++ b/src/main/java/world/bentobox/bentobox/nms/v1_21_R0_1_SNAPSHOT/PasteHandlerImpl.java
@@ -0,0 +1,52 @@
+package world.bentobox.bentobox.nms.v1_21_R0_1_SNAPSHOT;
+
+import java.util.concurrent.CompletableFuture;
+
+import org.bukkit.Location;
+import org.bukkit.block.Block;
+import org.bukkit.block.data.BlockData;
+import org.bukkit.craftbukkit.v1_21_R1.CraftWorld;
+import org.bukkit.craftbukkit.v1_21_R1.block.data.CraftBlockData;
+
+import net.minecraft.core.BlockPosition;
+import net.minecraft.world.level.block.state.IBlockData;
+import net.minecraft.world.level.chunk.Chunk;
+import world.bentobox.bentobox.blueprints.dataobjects.BlueprintBlock;
+import world.bentobox.bentobox.database.objects.Island;
+import world.bentobox.bentobox.nms.PasteHandler;
+import world.bentobox.bentobox.util.DefaultPasteUtil;
+import world.bentobox.bentobox.util.Util;
+
+public class PasteHandlerImpl implements PasteHandler {
+
+    protected static final IBlockData AIR = ((CraftBlockData) AIR_BLOCKDATA).getState();
+
+    /**
+     * Set the block to the location
+     *
+     * @param island   - island
+     * @param location - location
+     * @param bpBlock  - blueprint block
+     */
+    @Override
+    public CompletableFuture<Void> setBlock(Island island, Location location, BlueprintBlock bpBlock) {
+        return Util.getChunkAtAsync(location).thenRun(() -> {
+            Block block = location.getBlock();
+            // Set the block data - default is AIR
+            BlockData bd = DefaultPasteUtil.createBlockData(bpBlock);
+            CraftBlockData craft = (CraftBlockData) bd;
+            net.minecraft.world.level.World nmsWorld = ((CraftWorld) location.getWorld()).getHandle();
+            Chunk nmsChunk = nmsWorld.d(location.getBlockX() >> 4, location.getBlockZ() >> 4);
+            BlockPosition bp = new BlockPosition(location.getBlockX(), location.getBlockY(), location.getBlockZ());
+            // Setting the block to air before setting to another state prevents some console errors
+            nmsChunk.a(bp, AIR, false);
+            nmsChunk.a(bp, craft.getState(), false);
+            block.setBlockData(bd, false);
+            DefaultPasteUtil.setBlockState(island, block, bpBlock);
+            // Set biome
+            if (bpBlock.getBiome() != null) {
+                block.setBiome(bpBlock.getBiome());
+            }
+        });
+    }
+}
diff --git a/src/main/java/world/bentobox/bentobox/nms/v1_21_R0_1_SNAPSHOT/WorldRegeneratorImpl.java b/src/main/java/world/bentobox/bentobox/nms/v1_21_R0_1_SNAPSHOT/WorldRegeneratorImpl.java
new file mode 100644
index 000000000..6e1e3855f
--- /dev/null
+++ b/src/main/java/world/bentobox/bentobox/nms/v1_21_R0_1_SNAPSHOT/WorldRegeneratorImpl.java
@@ -0,0 +1,26 @@
+package world.bentobox.bentobox.nms.v1_21_R0_1_SNAPSHOT;
+
+import org.bukkit.block.data.BlockData;
+import org.bukkit.craftbukkit.v1_21_R1.CraftWorld;
+import org.bukkit.craftbukkit.v1_21_R1.block.data.CraftBlockData;
+
+import net.minecraft.core.BlockPosition;
+import net.minecraft.world.level.World;
+import net.minecraft.world.level.chunk.Chunk;
+import world.bentobox.bentobox.nms.CopyWorldRegenerator;
+
+public class WorldRegeneratorImpl extends CopyWorldRegenerator {
+
+    @Override
+    public void setBlockInNativeChunk(org.bukkit.Chunk chunk, int x, int y, int z, BlockData blockData,
+            boolean applyPhysics) {
+        CraftBlockData craft = (CraftBlockData) blockData;
+        World nmsWorld = ((CraftWorld) chunk.getWorld()).getHandle();
+        Chunk nmsChunk = nmsWorld.d(chunk.getX(), chunk.getZ());
+        BlockPosition bp = new BlockPosition((chunk.getX() << 4) + x, y, (chunk.getZ() << 4) + z);
+        // Setting the block to air before setting to another state prevents some console errors
+        nmsChunk.a(bp, PasteHandlerImpl.AIR, applyPhysics);
+        nmsChunk.a(bp, craft.getState(), applyPhysics);
+    }
+
+}
\ No newline at end of file
diff --git a/src/main/resources/locales/en-US.yml b/src/main/resources/locales/en-US.yml
index 645ab8e53..1eb99735d 100644
--- a/src/main/resources/locales/en-US.yml
+++ b/src/main/resources/locales/en-US.yml
@@ -514,6 +514,7 @@ commands:
       addons: '[prefix_bentobox]&6 Migrating addons'
       class: '[prefix_bentobox]&6 Migrating [description]'
       migrated: '[prefix_bentobox]&a Migrated'
+      completed: '[prefix_bentobox]&a Completed'
     rank:
       description: 'list, add, or remove ranks'
       parameters: '&a [list | add | remove] [rank reference] [rank value]'