Hi Kazimierz Kosydor,

According to our support policy. User need to assign domain to your license to obtain for support. You can do so by accessing your license area at http://stackideas.com/dashboard

Once you are done, update us here and we'll continue checking your issue.

Thanks for understanding

I assigned domain to license.

Try copy this following file and replace into JoomlaFolder\administrator\components\com_easyblog\includes\composer\composer.php and see how it goes?

Note: If you open composer from backend, you have to override your category language constant into backend as well.