diff --git a/DragonECS.csproj b/DragonECS.csproj
index 129c906..55f91c7 100644
--- a/DragonECS.csproj
+++ b/DragonECS.csproj
@@ -10,7 +10,7 @@
         <RootNamespace>DCFApixels.DragonECS</RootNamespace>
 
         <Title>DragonECS</Title>
-        <Version>0.8.39</Version>
+        <Version>0.8.41</Version>
         <Authors>DCFApixels</Authors>
         <Description>ECS Framework for Game Engines with C# and .Net Platform</Description>
         <Copyright>DCFApixels</Copyright>
diff --git a/README-ZN.md.meta b/README-ZN.md.meta
new file mode 100644
index 0000000..d66037d
--- /dev/null
+++ b/README-ZN.md.meta
@@ -0,0 +1,7 @@
+fileFormatVersion: 2
+guid: 877c188fb31b69045adeec8ca9a19b33
+TextScriptImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/package.json b/package.json
index b811349..0610af7 100644
--- a/package.json
+++ b/package.json
@@ -8,7 +8,7 @@
     "displayName": "DragonECS",
     "description": "C# Entity Component System Framework",
     "unity": "2020.3",
-    "version": "0.8.39",
+    "version": "0.8.41",
     "repository": {
         "type": "git",
         "url": "https://github.com/DCFApixels/DragonECS.git"
diff --git a/src/EcsWorld.cs b/src/EcsWorld.cs
index 8e63f57..24ac88e 100644
--- a/src/EcsWorld.cs
+++ b/src/EcsWorld.cs
@@ -373,14 +373,14 @@ namespace DCFApixels.DragonECS
 #if (DEBUG && !DISABLE_DEBUG) || !DISABLE_DRAGONECS_ASSERT_CHEKS
             if (mask._worldID != id) { Throw.World_MaskDoesntBelongWorld(); }
 #endif
-            for (int i = 0, iMax = mask._incChunckMasks.Length; i < iMax; i++)
+            for (int i = 0, iMax = mask._inc.Length; i < iMax; i++)
             {
                 if (!_pools[mask._inc[i]].Has(entityID))
                 {
                     return false;
                 }
             }
-            for (int i = 0, iMax = mask._excChunckMasks.Length; i < iMax; i++)
+            for (int i = 0, iMax = mask._exc.Length; i < iMax; i++)
             {
                 if (_pools[mask._exc[i]].Has(entityID))
                 {
@@ -553,9 +553,12 @@ namespace DCFApixels.DragonECS
             }
             for (int i = 0; i < _groups.Count; i++)
             {
-                if (_groups[i].TryGetTarget(out EcsGroup group) && group.IsReleased)
+                if (_groups[i].TryGetTarget(out EcsGroup group))
                 {
-                    group.OnReleaseDelEntityBuffer_Internal(buffer);
+                    if(group.IsReleased)
+                    {
+                        group.OnReleaseDelEntityBuffer_Internal(buffer);
+                    }
                 }
                 else
                 {