Hi,
I have a light website built by K2 on Joomla 3.8. I have set Joomla's SEO Settings to "Search Engine Friendly URLs". I have made a category "myblog" in k2 and created a bunch of items. I have also made a menu for myblog category. So in the frontend urls look like this:

www.mysite.com/myblog/05-my-blog-item

But Google webmaster shows that all of my K2 items have a duplicate url that look like this:

www.mysite.com/component/k2/05-my-blog-item

I know the topic of duplicate urls have been discussed before but after reading all of them I still dont know if this happens to everyone or just some sites! and what is the root cause of this? is this fixable with re-configuration of menus or k2 categories or only fixable with 3rd-party extensions?

Thanks

Hello,

All extensions have hackable URLs, you can solve this by,
a) Submit a sitemap.xml in Google's WMT and stop the Googlebot from accessing your site or
b) Use a 3rd party SEO extension which supports K2 or
c) Use an SEO extension which produces valid canonical links for K2.

It is very simple. In the robots.txt write tihs:

Disallow: /component/

And if you want to properly configure robots.txt for Joomla and K2 write this:

User-agent: *
Allow: *Your sitemap URL*
Disallow: /administrator/
Disallow: /bin/
Disallow: /cache/
Disallow: /cli/
Disallow: /component/k2/itemlist/tag/
Disallow: /component/
Disallow: /images/
Disallow: /component/tags*
Disallow: /components/
Disallow: /includes/
Disallow: /installation/
Disallow: /language/
Disallow: /layouts/
Disallow: /libraries/
Disallow: /logs/
Disallow: /tmp/
Disallow: /*%
Disallow: /?start
Disallow: /?
Disallow: /index.php?
Disallow: /*?
Disallow: /index.php*?
Disallow: /item
Disallow: /item/


So there will be no duplicates at all.

Nice one Vlad.
But you might still get duplicates if there is an issue with your menu setup.
A canonical link will also solve the already indexed links as well.