diff --git a/AutoConfig.py b/AutoConfig.py
index 406ceb8..56117ea 100755
--- a/AutoConfig.py
+++ b/AutoConfig.py
@@ -17,6 +17,7 @@ import json
 import traceback
 import urllib.request
 import requests
+import updatekiller
 import PyQt5.QtWidgets as QtWidgets
 from UI.AutoConfig import *
 from Model import *
@@ -24,7 +25,7 @@ try:
     import PyQt5.QtWebEngineWidgets as QtWebEngineWidgets
     webeng = True
 except:
-    print("未安装此依赖库")
+    print("未安装 QtWebEngine")    #这样更容易排查问题
     webeng = False
 print("""太常引·建康中秋夜为吕叔潜赋
 一轮秋影转金波，飞镜又重磨。把酒问姮娥：被白发、欺人奈何？
@@ -525,7 +526,8 @@ def ChangeSources():
     sources = [ui.actionGitlink, ui.actionGitee, ui.actionGithub, ui.action_IPv6, ui.action_2, ui.action_3, ui.action]
     for i in range(0, len(sources)):
         if sources[i].isChecked():
-            urlSources = urlSourcesList[i]
+            old_urlSources = urlSources     #先备份
+            urlSources = urlSourcesList[i]  #然后切换尝试
             # 解析云列表
             try:
                 # 获取列表
@@ -538,6 +540,7 @@ def ChangeSources():
             except:
                 traceback.print_exc()
                 QtWidgets.QMessageBox.critical(window, "提示", "无法连接服务器")
+                urlSources = old_urlSources     #如果源不可用则换回来
             break
 
 if __name__ == "__main__":
@@ -596,4 +599,4 @@ if __name__ == "__main__":
         traceback.print_exc()
         QtWidgets.QMessageBox.critical(window, "提示", "无法连接服务器")
     
-    app.exec_()
\ No newline at end of file
+    app.exec_()
diff --git a/README.md b/README.md
index bcd297e..2966ab3 100755
--- a/README.md
+++ b/README.md
@@ -48,7 +48,7 @@ sudo apt upgrade
   
 ### 三、使用程序自带的更新程序更新  
   
-**1、打开 UEngine 运行器然后点击“关于”=>“检查更新”，点击“更新（更新过程中会关闭所有Python应用，包括这个应用）”**    
+**1、打开 UEngine 运行器然后点击“关于”=>“检查更新”，点击“更新（更新过程中会关闭这个应用的所有进程）”**    
 ![image.png](https://storage.deepin.org/thread/202205220759382269_image.png)    
 **2、输入密码进行更新**    
 ![image.png](https://storage.deepin.org/thread/202205220801175784_image.png)