diff --git a/Editor/Settings/HybridCLRSettingProvider.cs b/Editor/Settings/HybridCLRSettingProvider.cs
index 78ccfd7..9484772 100644
--- a/Editor/Settings/HybridCLRSettingProvider.cs
+++ b/Editor/Settings/HybridCLRSettingProvider.cs
@@ -26,7 +26,7 @@ namespace HybridCLR.Editor
             HybridCLRSettings.Instance.Save();
             var setting = HybridCLRSettings.Instance;
             setting.hideFlags &= ~HideFlags.NotEditable;
-            m_SerializedObject ??= new SerializedObject(setting);
+            m_SerializedObject = m_SerializedObject ?? new SerializedObject(setting);
             m_Enable = m_SerializedObject.FindProperty("enable");
             m_UseGlobalIl2cpp = m_SerializedObject.FindProperty("useGlobalIl2cpp");
             m_CloneFromGitee = m_SerializedObject.FindProperty("cloneFromGitee");
@@ -42,7 +42,7 @@ namespace HybridCLR.Editor
         {
             base.OnTitleBarGUI();
             var rect = GUILayoutUtility.GetLastRect();
-            buttonStyle ??= GUI.skin.GetStyle("IconButton");
+            buttonStyle = buttonStyle ?? GUI.skin.GetStyle("IconButton");
 
             #region  绘制官方网站跳转按钮
             var w = rect.x + rect.width;
@@ -135,7 +135,7 @@ namespace HybridCLR.Editor
             {
                 var provider = new HybridCLRSettingsProvider
                 {
-                    keywords = GetSearchKeywordsFromSerializedObject(m_SerializedObject ??= new SerializedObject(HybridCLRSettings.Instance))
+                    keywords = GetSearchKeywordsFromSerializedObject(m_SerializedObject = m_SerializedObject ?? new SerializedObject(HybridCLRSettings.Instance))
                 };
                 return provider;
             }
diff --git a/Editor/Settings/SettingsPresetReceiver.cs b/Editor/Settings/SettingsPresetReceiver.cs
index 3636c49..592ae64 100644
--- a/Editor/Settings/SettingsPresetReceiver.cs
+++ b/Editor/Settings/SettingsPresetReceiver.cs
@@ -26,7 +26,9 @@ namespace HybridCLR.Editor
                 Undo.RecordObject(m_Target, "Cancel Preset");
                 m_InitialValue.ApplyTo(m_Target);
             }
+#if UNITY_2020_1_OR_NEWER
             SettingsService.RepaintAllSettingsWindow();
+#endif
         }
         public override void OnSelectionClosed(Preset selection)
         {
diff --git a/package.json b/package.json
index 8ac6e9c..b2d2401 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "com.focus-creative-games.hybridclr_unity",
-  "version": "0.3.8",
+  "version": "0.3.9",
   "displayName": "HybridCLR",
   "description": "Unity package for HybridCLR. It includes editor and runtime scripts and assets for HybridCLR",
   "category": "Runtime",