title: import matplotlib.pyplot as plt failed
body: <pre><code>File "&lt;stdin&gt;", line 1, in &lt;module&gt;
    File "C:\Users\franc\Anaconda3\lib\site-packages\matplotlib\pyplot.py", line 32, in &lt;module&gt;
      import matplotlib.colorbar
    File "C:\Users\franc\Anaconda3\lib\site-packages\matplotlib\colorbar.py", line 32, in &lt;module&gt;
      import matplotlib.contour as contour
    File "C:\Users\franc\Anaconda3\lib\site-packages\matplotlib\contour.py", line 18, in &lt;module&gt;
      import matplotlib.font_manager as font_manager
    File "C:\Users\franc\Anaconda3\lib\site-packages\matplotlib\font_manager.py", line 1363, in &lt;module&gt;
      _rebuild()
    File "C:\Users\franc\Anaconda3\lib\site-packages\matplotlib\font_manager.py", line 1344, in _rebuild
      fontManager = FontManager()
    File "C:\Users\franc\Anaconda3\lib\site-packages\matplotlib\font_manager.py", line 978, in __init__
      ttffiles = findSystemFonts(paths) + findSystemFonts()
    File "C:\Users\franc\Anaconda3\lib\site-packages\matplotlib\font_manager.py", line 264, in findSystemFonts
      fontfiles.update(win32InstalledFonts(fontext=fontext))
  TypeError: 'NoneType' object is not iterable
  </code></pre>
  
  <p>I've tried to uninstall and reinstall <code>matplotlib</code> in many ways, but I still get the above error. </p>