diff --git a/src/EcsMask.cs b/src/EcsMask.cs
index cb43005..1c72299 100644
--- a/src/EcsMask.cs
+++ b/src/EcsMask.cs
@@ -497,7 +497,13 @@ namespace DCFApixels.DragonECS
         /// <summary> slised _sortIncChunckBuffer </summary>
         private readonly UnsafeArray<EcsMaskChunck> _sortExcChunckBuffer;
 
-        private readonly bool _isOnlyInc;
+        private readonly MaskType _maskType;
+        private enum MaskType : byte
+        {
+            Empty,
+            OnlyInc,
+            IncExc,
+        }
 
         #region Constructors/Finalizator
         public unsafe EcsMaskIterator(EcsWorld source, EcsMask mask)
@@ -523,7 +529,14 @@ namespace DCFApixels.DragonECS
             _sortExcChunckBuffer = sortChunckBuffer.Slice(mask._incChunckMasks.Length, mask._excChunckMasks.Length);
             _sortExcChunckBuffer.CopyFromArray_Unchecked(mask._excChunckMasks);
 
-            _isOnlyInc = _sortExcBuffer.Length <= 0;
+            if (_sortExcBuffer.Length <= 0)
+            {
+                _maskType = mask.IsEmpty ? MaskType.Empty : MaskType.OnlyInc;
+            }
+            else
+            {
+                _maskType = MaskType.IncExc;
+            }
         }
         unsafe ~EcsMaskIterator()
         {
@@ -589,25 +602,36 @@ namespace DCFApixels.DragonECS
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void IterateTo(EcsSpan source, EcsGroup group)
         {
-            if (_isOnlyInc)
+            switch (_maskType)
             {
-                IterateOnlyInc(source).CopyTo(group);
-            }
-            else
-            {
-                Iterate(source).CopyTo(group);
+                case MaskType.Empty:
+                    group.CopyFrom(source);
+                    break;
+                case MaskType.OnlyInc:
+                    IterateOnlyInc(source).CopyTo(group);
+                    break;
+                case MaskType.IncExc:
+                    Iterate(source).CopyTo(group);
+                    break;
+                default:
+                    Throw.UndefinedException();
+                    break;
             }
         }
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public int IterateTo(EcsSpan source, ref int[] array)
         {
-            if (_isOnlyInc)
+            switch (_maskType)
             {
-                return IterateOnlyInc(source).CopyTo(ref array);
-            }
-            else
-            {
-                return Iterate(source).CopyTo(ref array);
+                case MaskType.Empty:
+                    return source.ToArray(ref array);
+                case MaskType.OnlyInc:
+                    return IterateOnlyInc(source).CopyTo(ref array);
+                case MaskType.IncExc:
+                    return Iterate(source).CopyTo(ref array);
+                default:
+                    Throw.UndefinedException();
+                    return 0;
             }
         }
         #endregion
diff --git a/src/Executors/EcsWhereExecutor.cs b/src/Executors/EcsWhereExecutor.cs
index 936abc4..bc9bc50 100644
--- a/src/Executors/EcsWhereExecutor.cs
+++ b/src/Executors/EcsWhereExecutor.cs
@@ -23,6 +23,8 @@ namespace DCFApixels.DragonECS.Internal
         private long _version;
         private WorldStateVersionsChecker _versionsChecker;
 
+        public bool _isDestroyed = false;
+
         #region Properties
         public sealed override long Version
         {
@@ -49,6 +51,8 @@ namespace DCFApixels.DragonECS.Internal
         }
         protected sealed override void OnDestroy()
         {
+            if (_isDestroyed) { return; }
+            _isDestroyed = true;
             _versionsChecker.Dispose();
         }
         #endregion
diff --git a/src/Executors/EcsWhereToGroupExecutor.cs b/src/Executors/EcsWhereToGroupExecutor.cs
index 7f626e0..8511206 100644
--- a/src/Executors/EcsWhereToGroupExecutor.cs
+++ b/src/Executors/EcsWhereToGroupExecutor.cs
@@ -20,6 +20,8 @@ namespace DCFApixels.DragonECS.Internal
         private long _version;
         private WorldStateVersionsChecker _versionsChecker;
 
+        public bool _isDestroyed = false;
+
         #region Properties
         public sealed override long Version
         {
@@ -47,6 +49,8 @@ namespace DCFApixels.DragonECS.Internal
         }
         protected sealed override void OnDestroy()
         {
+            if (_isDestroyed) { return; }
+            _isDestroyed = true;
             _filteredAllGroup.Dispose();
             _versionsChecker.Dispose();
         }
diff --git a/src/Executors/MaskQueryExecutor.cs b/src/Executors/MaskQueryExecutor.cs
index be20d3f..d6f70f2 100644
--- a/src/Executors/MaskQueryExecutor.cs
+++ b/src/Executors/MaskQueryExecutor.cs
@@ -200,7 +200,7 @@ namespace DCFApixels.DragonECS.Core
 
         public void Dispose()
         {
-
+            UnmanagedArrayUtility.Free(_versions);
         }
     }
 }
\ No newline at end of file
diff --git a/src/Internal/ArrayUtility.cs b/src/Internal/ArrayUtility.cs
index 51d04a3..43aac30 100644
--- a/src/Internal/ArrayUtility.cs
+++ b/src/Internal/ArrayUtility.cs
@@ -203,7 +203,9 @@ namespace DCFApixels.DragonECS.Internal
             byte* newPointer = (byte*)Marshal.AllocHGlobal(newSize).ToPointer();
 
             for (int i = 0; i < newSize; i++)
+            {
                 *(newPointer + i) = 0;
+            }
 
             return (T*)newPointer;
         }
@@ -214,7 +216,9 @@ namespace DCFApixels.DragonECS.Internal
             byte* newPointer = (byte*)Marshal.AllocHGlobal(newSize).ToPointer();
 
             for (int i = 0; i < newSize; i++)
+            {
                 *(newPointer + i) = 0;
+            }
 
             ptr = (T*)newPointer;
         }
@@ -250,8 +254,6 @@ namespace DCFApixels.DragonECS.Internal
                 new IntPtr(oldPointer),
                 new IntPtr(MetaCache<T>.Size * newCount))).ToPointer();
         }
-
-
     }
 
     public static class CollectionUtility