An issue with Polylang and theme translation

there’s a website on custom theme and the Polylang plugin. It was good when I used for couple months. While changing the language it translated such code

<?php _e('Hello!','themedomain'); ?>

Then something went wrong and it stopped translating. .mo and .po files didn’t change, code too. But now it stopped to translate expressions.

Polylang 2.0.4, WordPress 4.6.1

Loading text domain:

add_action( 'after_setup_theme', 'mytheme_setup' );
if ( ! function_exists( 'mytheme_setup' ) ):
function mytheme_setup() {
    add_editor_style();
    add_theme_support( 'post-thumbnails' );
    add_theme_support( 'automatic-feed-links' );
    $path = get_template_directory() . '/languages';
    //$result = load_theme_textdomain('themedomain', $path );
    //if ( $result )
     //return;
    //$locale = apply_filters( 'theme_locale', get_locale(), 'themedomain' );
    //die( "Could not find $path/$locale.mo." );
    load_theme_textdomain('themedomain', $path );
    //if ( is_readable( "$path/$locale.mo")) { echo "+"; } else { echo "-"; };  
}
endif;

If I uncomment this

//$result = load_theme_textdomain('themedomain', $path );
//if ( $result )
 //return;
//$locale = apply_filters( 'theme_locale', get_locale(), 'themedomain' );
//die( "Could not find $path/$locale.mo." );

it shows “Could not find /the/full/path/ru_RU.mo”, however another language is chosen.

If I uncomment this

//if ( is_readable( "$path/$locale.mo")) { echo "+"; } else { echo "-"; };

it shows –

Files permissions are 666, ‘languages’ directory is 777.