diff --git a/core/src/main/java/com/boydti/fawe/logging/rollback/RollbackOptimizedHistory.java b/core/src/main/java/com/boydti/fawe/logging/rollback/RollbackOptimizedHistory.java
index c27378bc..712a2a5e 100644
--- a/core/src/main/java/com/boydti/fawe/logging/rollback/RollbackOptimizedHistory.java
+++ b/core/src/main/java/com/boydti/fawe/logging/rollback/RollbackOptimizedHistory.java
@@ -85,7 +85,9 @@ public class RollbackOptimizedHistory extends DiskStorageHistory {
         if (super.close()) {
             // Save to DB
             RollbackDatabase db = DBHandler.IMP.getDatabase(getWorld());
-            db.logEdit(this);
+            if (db != null) {
+                db.logEdit(this);
+            }
             return true;
         }
         return false;
diff --git a/forge111/src/main/java/com/boydti/fawe/forge/v111/ForgeChunk_All.java b/forge111/src/main/java/com/boydti/fawe/forge/v111/ForgeChunk_All.java
index 3049425c..4c2e7a35 100644
--- a/forge111/src/main/java/com/boydti/fawe/forge/v111/ForgeChunk_All.java
+++ b/forge111/src/main/java/com/boydti/fawe/forge/v111/ForgeChunk_All.java
@@ -256,23 +256,27 @@ public class ForgeChunk_All extends CharFaweChunk<Chunk, ForgeQueue_All> {
                 getParent().getChangeTask().run(previous, this);
             }
             // Trim tiles
-            Set<Map.Entry<BlockPos, TileEntity>> entryset = tiles.entrySet();
-            Iterator<Map.Entry<BlockPos, TileEntity>> iterator = entryset.iterator();
-            while (iterator.hasNext()) {
-                Map.Entry<BlockPos, TileEntity> tile = iterator.next();
-                BlockPos pos = tile.getKey();
-                int lx = pos.getX() & 15;
-                int ly = pos.getY();
-                int lz = pos.getZ() & 15;
-                int j = FaweCache.CACHE_I[ly][lz][lx];
-                char[] array = this.getIdArray(j);
-                if (array == null) {
-                    continue;
-                }
-                int k = FaweCache.CACHE_J[ly][lz][lx];
-                if (array[k] != 0) {
-                    tile.getValue().invalidate();;
-                    iterator.remove();
+            if (!tiles.isEmpty()) {
+                Set<Map.Entry<BlockPos, TileEntity>> entryset = tiles.entrySet();
+                Iterator<Map.Entry<BlockPos, TileEntity>> iterator = entryset.iterator();
+                while (iterator.hasNext()) {
+                    Map.Entry<BlockPos, TileEntity> tile = iterator.next();
+                    BlockPos pos = tile.getKey();
+                    int lx = pos.getX() & 15;
+                    int ly = pos.getY();
+                    int lz = pos.getZ() & 15;
+                    int j = FaweCache.CACHE_I[ly][lz][lx];
+                    char[] array = this.getIdArray(j);
+                    if (array == null) {
+                        continue;
+                    }
+                    int k = FaweCache.CACHE_J[ly][lz][lx];
+                    if (array[k] != 0) {
+                        synchronized (ForgeChunk_All.class) {
+                            tile.getValue().invalidate();
+                            iterator.remove();
+                        }
+                    }
                 }
             }
             // Efficiently merge sections
diff --git a/sponge/src/main/java/com/boydti/fawe/sponge/v1_11/SpongeChunk_1_11.java b/sponge/src/main/java/com/boydti/fawe/sponge/v1_11/SpongeChunk_1_11.java
index 97fbf74f..2537860c 100644
--- a/sponge/src/main/java/com/boydti/fawe/sponge/v1_11/SpongeChunk_1_11.java
+++ b/sponge/src/main/java/com/boydti/fawe/sponge/v1_11/SpongeChunk_1_11.java
@@ -256,23 +256,27 @@ public class SpongeChunk_1_11 extends CharFaweChunk<Chunk, SpongeQueue_1_11> {
                 getParent().getChangeTask().run(previous, this);
             }
             // Trim tiles
-            Set<Map.Entry<BlockPos, TileEntity>> entryset = tiles.entrySet();
-            Iterator<Map.Entry<BlockPos, TileEntity>> iterator = entryset.iterator();
-            while (iterator.hasNext()) {
-                Map.Entry<BlockPos, TileEntity> tile = iterator.next();
-                BlockPos pos = tile.getKey();
-                int lx = pos.getX() & 15;
-                int ly = pos.getY();
-                int lz = pos.getZ() & 15;
-                int j = FaweCache.CACHE_I[ly][lz][lx];
-                char[] array = this.getIdArray(j);
-                if (array == null) {
-                    continue;
-                }
-                int k = FaweCache.CACHE_J[ly][lz][lx];
-                if (array[k] != 0) {
-                    tile.getValue().invalidate();;
-                    iterator.remove();
+            if (!tiles.isEmpty()) {
+                Set<Map.Entry<BlockPos, TileEntity>> entryset = tiles.entrySet();
+                Iterator<Map.Entry<BlockPos, TileEntity>> iterator = entryset.iterator();
+                while (iterator.hasNext()) {
+                    Map.Entry<BlockPos, TileEntity> tile = iterator.next();
+                    BlockPos pos = tile.getKey();
+                    int lx = pos.getX() & 15;
+                    int ly = pos.getY();
+                    int lz = pos.getZ() & 15;
+                    int j = FaweCache.CACHE_I[ly][lz][lx];
+                    char[] array = this.getIdArray(j);
+                    if (array == null) {
+                        continue;
+                    }
+                    int k = FaweCache.CACHE_J[ly][lz][lx];
+                    if (array[k] != 0) {
+                        synchronized (SpongeChunk_1_11.class) {
+                            tile.getValue().invalidate();
+                            iterator.remove();
+                        }
+                    }
                 }
             }
             HashSet<UUID> entsToRemove = this.getEntityRemoves();