If you get an error like:

XML Parsing Error: xml declaration not at start of external entity
Location: http://10.2.48.69/hdwiki//index.php?…anges&feed=rss
Line Number 1, Column 2: <?xml version=”1.0″ encoding=”utf-8″?>
-^

When clicking the rss or atom link in your toolbox from the Recent Changes page, you probably have an extra blank line, either before the <? php tag or after ?> tag in one of your settings files or extension files for your MediaWiki.

In my case, I found it in my EasyTimeline Timeline.php extension file. I had two blank lines at the end. Erasing those lines and re-saving the file fixed the issue.

See uncle Google for more information, but the discussion I referred to to fix my issue was here.