title: How is my user.config Settings file getting corrupted?
body: <p>I've had a user send me in a crash report from a call to <code>Settings.Upgrade()</code>:</p>
  
  <pre>
  System.Configuration.ConfigurationErrorsException: Root element is missing.
  </pre>
  
  <p>I got him to send me his user.config file and the file was all zeroes. It had gotten corrupt somehow.</p>
  
  <p>I found a way to recover from it by rooting around the %localappdata%\MyAppName directory and deleting all user config files and re-launching the app. If I let the app continue execution it would give further <code>ConfigurationErrorsException</code>s.</p>
  
  <p>Could this corruption be the result of something I've done? I've had multiple reports of it from a base of a few thousand users, but I have not been messing with that file directly. Has anyone else run into this user.config corruption?</p>