Interestingly, they also noted:
This is one of those rare instances where Google shares a direct negative ranking factor.
(editor's note: wp-includes and wp-content should be highlighted, not wp-admin)
This has been a very common and regularly recommended practice for preventing sensitive directories from being easily discovered by hackers.
To see if you might have this problem, navigate to:
If you see:
Once you've resolved the blocking problem, head over to Google Webmaster Tools and navigate to:
Crawl >> Fetch as Google
If you see Googlebot couldn't get all resources for this page. Here's a list:
I'm skeptical that this will give you a huge rankings / traffic boost (but if it does, please let us know in the comments). However, in a competitive landscape, every little bit can help.
It's a good practice to regularly fetch and render your site(s) in Google Webmaster Tools. Be sure to review the code that's generated under the "Fetching" tab. This is how Google sees your pages. Make sure that the information that you are sending to Google is what you want Google to see.
Don't forget to use Fetch and Render for both Desktop and Mobile. As the web increasingly goes mobile, search engines will continue to evolve to understand whether your pages are optimized for mobile, which can also impact rankings.
Site updates and inadvertent configuration mistakes can have a serious impact on your sites' ability to appear in search results. The good news is that with regular maintenance, most of these issues are fairly easily to remedy.