diff --git a/Editor/UI/Settings/AutopilotSettingsEditor.cs b/Editor/UI/Settings/AutopilotSettingsEditor.cs
index 1d32be5..7e577d7 100644
--- a/Editor/UI/Settings/AutopilotSettingsEditor.cs
+++ b/Editor/UI/Settings/AutopilotSettingsEditor.cs
@@ -145,7 +145,9 @@ internal void Launch()
             else
             {
                 state.launchFrom = LaunchType.EditMode;
+#if UNITY_2020_3_OR_NEWER
                 AssetDatabase.SaveAssetIfDirty(state); // Note: Sync with virtual players of MPPM package
+#endif
                 EditorApplication.isPlaying = true;
             }
         }
diff --git a/Runtime/Launcher.cs b/Runtime/Launcher.cs
index f55fcb2..8750e86 100644
--- a/Runtime/Launcher.cs
+++ b/Runtime/Launcher.cs
@@ -224,7 +224,7 @@ internal static async UniTaskVoid TeardownLaunchAutopilotAsync(AutopilotState st
         {
             state.settings = null;
             state.exitCode = exitCode;
-#if UNITY_EDITOR
+#if UNITY_EDITOR && UNITY_2020_3_OR_NEWER
             AssetDatabase.SaveAssetIfDirty(state); // Note: Sync with virtual players of MPPM package
 #endif
 
diff --git a/Runtime/Settings/AutopilotSettings.cs b/Runtime/Settings/AutopilotSettings.cs
index 385e358..af31ac9 100644
--- a/Runtime/Settings/AutopilotSettings.cs
+++ b/Runtime/Settings/AutopilotSettings.cs
@@ -323,7 +323,7 @@ private static void Initialize()
             settings.ConvertSceneCrossingAgentsFromObsoleteObserverAgent(logger); // Note: before convert other Agents.
             settings.ConvertErrorHandlerAgentFromObsoleteSettings(logger);
 
-#if UNITY_EDITOR
+#if UNITY_EDITOR && UNITY_2020_3_OR_NEWER
             AssetDatabase.SaveAssetIfDirty(settings);
 #endif
         }
diff --git a/Runtime/Settings/AutopilotState.cs b/Runtime/Settings/AutopilotState.cs
index 11e4d98..ed94e6c 100644
--- a/Runtime/Settings/AutopilotState.cs
+++ b/Runtime/Settings/AutopilotState.cs
@@ -46,7 +46,7 @@ public void Reset()
             launchFrom = LaunchType.NotSet;
             settings = null;
             exitCode = ExitCode.Normally;
-#if UNITY_EDITOR
+#if UNITY_EDITOR && UNITY_2020_3_OR_NEWER
             AssetDatabase.SaveAssetIfDirty(this); // Note: Sync with virtual players of MPPM package
 #endif
         }