[Plugin: nrelate Related Content] Plugin says "no posts", when are many posts…

Information from my nRelate dashboard: Thanks for installing nRelate. We are ready but we did not find any posts. Once you start publishing posts, you will see our widget. Contact us for questions and comments.
It’s completely strange, because my site has more than 20 posts now .
It worked earlier, few hours ago, but I wanted to re-index my site and after this I see this instruction in dashboard.
Uninstalled, delete nRelate_key from database and problem isn’t fixed.
Site is http://www.na-sygnale.pl . Could You check this, please ?