Well I found that the installer doesn't always insert the records in the jos_social_languages table in the database
manually copied it and it worked, so should be a bug

it will not auto retrieve those language data during the installation, you have to install it manually through your Joomla backend Easysocial language page.

By the way, it seems like you already start a new thread on our forums, I will response on your original thread.

As a gentle reminder, kindly start a new thread if you have any other issue in the future so it will be easier for us to manage your inquiry. I will lock and mark this thread as resolved.