Text domain not working

If someone need fep in his language need to find all translatable strings and add the text domain in it. Now it’s a big mess with the textdomains. There are FEP, ‘fep’ , but most are missing. after You fix this you need to load the .mo file something like this

add_action( 'plugins_loaded', 'fep_localization_init' );
function fep_localization_init() {
    $path = dirname(plugin_basename(__FILE__)) . '/languages/';
    load_plugin_textdomain( 'fep', false, $path );
}

https://wordpress.org/plugins/frontend-edit-profile/