title: Access is denied error windows phone 8
body: <p>I am getting error on following line</p>
  
  <p><strong>StorageFolder picturesFolder = KnownFolders.PicturesLibrary;</strong></p>
  
  <p>Exception is: 
  ex  {System.UnauthorizedAccessException: Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))
  at Windows.Storage.KnownFolders.get_PicturesLibrary()
  at WinTooth.MainPage.d__0.MoveNext()} System.SystemException {System.UnauthorizedAccessException}</p>
  
  <p>I have also added lines to register for a file association extension.
  Please suggest/help.</p>