diff --git a/game_config.json b/game_config.json
index 7f0214c..29e8c25 100644
--- a/game_config.json
+++ b/game_config.json
@@ -1,6 +1,6 @@
 {
   "game_name": "easy_game",
-  "version": "2.3.3-alpha",
+  "version": "2.3.4-alpha",
   "url": "https://github.com/PAIA-Playful-AI-Arena/easy_game",
   "description": "這是一個吃東西小遊戲，除了讓你熟習所有基本操作，也是 PAIA 的遊戲教學範例",
   "logo": [
diff --git a/src/game.py b/src/game.py
index cad6cf0..69dbba3 100644
--- a/src/game.py
+++ b/src/game.py
@@ -62,7 +62,7 @@ class EasyGame(PaiaGame):
             with open(os.path.join(LEVEL_PATH, "001.json")) as f:
                 game_params = json.load(f)
                 self._level = 1
-                self._level_file = None
+                self._level_file = ""
         finally:
             # set game params
             self._playground_w = int(game_params["playground_size"][0])