Ошибка Roundcube “openssl_decrypt()”

Версия roundcube 1.2.9-complete

Ошибка Roundcubе, после авторизации через веб-интерфейс такая ошибка (включен debug 4 уровня)

Warning: openssl_decrypt(): IV passed is 15 bytes long which is longer than the 8 expected by selected cipher, truncating in /var/www/roundcube/program/lib/Roundcube/rcube.php on line 874 
Warning: openssl_decrypt(): IV passed is 15 bytes long which is longer than the 8 expected by selected cipher, truncating in /var/www/roundcube/program/lib/Roundcube/rcube.php on line 874

Блок кода с 874 строчкой:

/**
     * Decrypt a string
     *
     * @param string  $cipher Encrypted text
     * @param string  $key    Encryption key to retrieve from the configuration, defaults to 'des_key'
     * @param boolean $base64 Whether or not input is base64-encoded
     *
     * @return string Decrypted text
     */
    public function decrypt($cipher, $key = 'des_key', $base64 = true)
    {
        if (!$cipher) {
            return '';
        }
        $cipher  = $base64 ? base64_decode($cipher) : $cipher;
        $ckey    = $this->config->get_crypto_key($key);
        $method  = $this->config->get_crypto_method();
        $opts    = defined('OPENSSL_RAW_DATA') ? OPENSSL_RAW_DATA : true;
        $iv_size = openssl_cipher_iv_length($method);
        $iv      = substr($cipher, 0, $iv_size);
        // session corruption? (#1485970)
        if (strlen($iv) < $iv_size) {
            return '';
        }
        $cipher = substr($cipher, $iv_size);
        $clear  = openssl_decrypt($cipher, $method, $ckey, $opts, $iv);
        return $clear;
    }

874 строчка

$clear  = openssl_decrypt($cipher, $method, $ckey, $opts, $iv);