diff --git a/logic/Gaming/Game.cs b/logic/Gaming/Game.cs
index a5a271a..70076ea 100644
--- a/logic/Gaming/Game.cs
+++ b/logic/Gaming/Game.cs
@@ -474,7 +474,7 @@ namespace Gaming
             var gameObjList = new List<IGameObj>();
             foreach (var keyValuePair in gameMap.GameObjDict)
             {
-                if (!GameData.IsMap(keyValuePair.Key))
+                if (GameData.NeedCopy(keyValuePair.Key))
                 {
                     gameMap.GameObjLockDict[keyValuePair.Key].EnterReadLock();
                     try
diff --git a/logic/Preparation/Utility/GameData.cs b/logic/Preparation/Utility/GameData.cs
index 32f631a..b1fb2c9 100644
--- a/logic/Preparation/Utility/GameData.cs
+++ b/logic/Preparation/Utility/GameData.cs
@@ -27,10 +27,13 @@ namespace Preparation.Utility
         public const int numOfGenerator = 9;
         public const int numOfChest = 8;
 
-        private const int numOfObjNotMap = 5;
         public static bool IsMap(GameObjType gameObjType)
         {
-            return (uint)gameObjType > numOfObjNotMap;
+            return (uint)gameObjType > 5;
+        }
+        public static bool NeedCopy(GameObjType gameObjType)
+        {
+            return gameObjType != GameObjType.Null && gameObjType != GameObjType.Grass && gameObjType != GameObjType.OutOfBoundBlock && gameObjType != GameObjType.Window && gameObjType != GameObjType.Wall;
         }
 
         public static XY GetCellCenterPos(int x, int y)  // 求格子的中心坐标
diff --git a/logic/Server/CopyInfo.cs b/logic/Server/CopyInfo.cs
index 23de73a..b6996f2 100644
--- a/logic/Server/CopyInfo.cs
+++ b/logic/Server/CopyInfo.cs
@@ -90,7 +90,6 @@ namespace Server
             }
         }
 
-
         public static Protobuf.PlayerState ToPlayerState(Preparation.Utility.PlayerStateType playerState)
         {
             switch (playerState)
@@ -238,10 +237,10 @@ namespace Server
                 case Preparation.Utility.GameObjType.EmergencyExit:
                     if (((EmergencyExit)gameObj).CanOpen)
                         return HiddenGate((EmergencyExit)gameObj);
-                    else return null;
+                    else return new MessageOfObj();
                 case Preparation.Utility.GameObjType.Door:
                     return Door((Door)gameObj);
-                default: return null;
+                default: return new MessageOfObj();
             }
         }
         public static MessageOfObj? Auto(MessageOfNews news)