新手学习python，遇到了灵异现象....同样的代码，隔夜运行突然报错。求教各位！

程序如下。。是一个简单的处理word页眉的脚本。该用例我跑了3、4天，都没出过问题。最近好像是win10系统升级了，我重装过一次office2013，但截至昨晚都是好的。。。今早起来报错。感谢各位！！帮忙看一下到底是那里出错了？

#coding:utf-8
import win32com
from win32com.client import Dispatch, constants

w = win32com.client.Dispatch('Word.Application')
doc = w.Documents.Open('D:/qq/1.docx')
myRange = doc.Range(0,0)
myRange.InsertBefore('Hello from Python!')
w.ActiveDocument.Sections[0].Headers[0].Range.Find.ClearFormatting()
w.ActiveDocument.Sections[0].Headers[0].Range.Find.Replacement.ClearFormatting()
w.ActiveDocument.Sections[0].Headers[0].Range.Find.Execute('22', False, False, False, False, False, True, 1, False, '11', 2)
# 保存文件
doc.SaveAs('D:/qq/1.docx')
#关闭文件
doc.Close()
#关闭Application
w.Quit()

==========错误信息，

Traceback (most recent call last):
  File "C:\Users\jiaze\Desktop\99.py", line 9, in <module>
    w.ActiveDocument.Sections[0].Headers[0].Range.Find.ClearFormatting()
  File "C:\Python27\lib\site-packages\win32com\client\__init__.py", line 473, in __getattr__
    raise AttributeError("'%s' object has no attribute '%s'" % (repr(self), attr))
AttributeError: '<win32com.gen_py.Microsoft Word 15.0 Object Library.Sections instance at 0x102718920>' object has no attribute '__getitem__'
[Finished in 2.5s with exit code 1]
[shell_cmd: python -u "C:\Users\jiaze\Desktop\99.py"]
[dir: C:\Users\jiaze\Desktop]
[path: C:\Python27\;C:\Python27\Scripts;C:\ProgramData\Oracle\Java\javapath;C:\Windows\System32;C:\Windows;C:\Windows\System32\wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\Windows\System32;C:\Windows;C:\Windows\System32\wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Users\jiaze


    
\AppData\Local\Microsoft\WindowsApps;;D:\Program Files (x86)\Fiddler;%USERPROFILE%\AppData\Local\Microsoft\WindowsApps]