title: ElementTree.ParseError while downloading NLTK Corpus
body: <p>I have installed <code>nltk 3.2.1</code> on my CentOS machine.<br>
  Now whenever I try to download any corpora/models of NLTK, it gives me below error:         </p>
  
  <pre><code>Traceback (most recent call last):
  File "/usr/lib64/python2.7/runpy.py", line 162, in _run_module_as_main
  "__main__", fname, loader, pkg_name)
  File "/usr/lib64/python2.7/runpy.py", line 72, in _run_code
  exec code in run_globals
  File "/usr/lib/python2.7/site-packages/nltk/downloader.py", line 2268, in &lt;module&gt;
  halt_on_error=options.halt_on_error)
  File "/usr/lib/python2.7/site-packages/nltk/downloader.py", line 664, in download
  for msg in self.incr_download(info_or_id, download_dir, force):
  File "/usr/lib/python2.7/site-packages/nltk/downloader.py", line 534, in incr_download
  try: info = self._info_or_id(info_or_id)
  File "/usr/lib/python2.7/site-packages/nltk/downloader.py", line 508, in _info_or_id
  return self.info(info_or_id)
  File "/usr/lib/python2.7/site-packages/nltk/downloader.py", line 875, in info
  self._update_index()
  File "/usr/lib/python2.7/site-packages/nltk/downloader.py", line 825, in _update_index
  ElementTree.parse(compat.urlopen(self._url)).getroot())
  File "/usr/lib64/python2.7/xml/etree/ElementTree.py", line 1182, in parse
  tree.parse(source, parser)
  File "/usr/lib64/python2.7/xml/etree/ElementTree.py", line 656, in parse
  parser.feed(data)
  File "/usr/lib64/python2.7/xml/etree/ElementTree.py", line 1642, in feed
  self._raiseerror(v)
  File "/usr/lib64/python2.7/xml/etree/ElementTree.py", line 1506, in _raiseerror
  raise err
  xml.etree.ElementTree.ParseError: syntax error: line 1, column 49
  </code></pre>
  
  <p>Note that I have tried all the below methods to download NLTK data -         </p>
  
  <ul>
  <li><code>nltk.download()</code></li>
  <li><code>nltk.download('all')</code></li>
  <li><code>python -m nltk.downloader all</code></li>
  </ul>
  
  <p>But in all the methods I receive the same error.<br>
  Anybody has any idea why I am getting this error and how to download NLTK data?<br>
  Any help would be appreciated!    </p>