title_body: The value following "version" in the XML declaration must be a quoted string
upvoted_answer: There doesn't appear to be an issue with the code after I tested it in a dummy ePub with ePubcheck 3.0.  Since you haven't mentioned how the ePub was created I would trouble shoot by:
  
  
  Creating a new XHTML file and re-doing the contents of the old XHTML file in it to make sure there isn't any issues with the file or if the file is corrupted.  
  Check to make sure your closing tag is proper or the document ends with &lt;/html&gt;.  This can be tested by opening the XHTML file in a browser such as Chrome and you might get a code error in red at the top.
  Sometimes empty lines after &lt;/html&gt; can cause a validation issue with ePubcheck so make sure to remove them.
  If this was created in an application like Sublime or BBEdit you can always validate the XHTML.