Your server closed the connection before we could receive a full response, and the body of the response appears to be truncated.
Use Fetch as Google to check if Googlebot can currently crawl your site. If Fetch as Google returns the content of your homepage without problems, you can assume that Google is generally able to access your site properly.
It’s possible that your server is overloaded or misconfigured. If the problem persists, check with your hosting provider.