Hello , 

This issue has been solved , to fix it in your server please replace the source code in the following path with   :

Path : application/modules/nstranslator/helpers/translator_helper.php

<?php
/** * Created by PhpStorm. * User: Amine * Date: 11/15/2017 * Time: 23:00 */
class Translate {
    /*     * DEBUGGING MODE     */    public static $in_debugging_mode = FALSE;
    public static $_translate_data_array = array();
    /*     *  $_translate_data_array = array(     *      code => data list     *  )     */
    public static function init(){
        /*         * JSON PATH         */
        $default_language_path_json = Path::getPath(array('uploads','translates'));
        //create a default folder if needed        if(!is_dir($default_language_path_json))            @mkdir($default_language_path_json);
        //get saved json data        $default_language_path_json = Path::getPath(array('uploads','translates',self::getDefaultLang().'.json'));
        //check if the file already exists to avoid problems, we can regenerated        // from yaml or getting the yaml data        if(!file_exists($default_language_path_json)){
            //regenerate from yaml files            $data = self::loadLanguageFromYml();            $data_json = json_encode($data,JSON_FORCE_OBJECT);            @file_put_contents($default_language_path_json,$data_json);
            self::$_translate_data_array = $data;
        }else{
            $default_language_data = file_get_contents($default_language_path_json);            $default_language_data = json_decode($default_language_data,JSON_OBJECT_AS_ARRAY);            self::$_translate_data_array = $default_language_data;
        }
    }
    public static function save($code,$data){
        $default_language_path_json = Path::getPath(array('uploads','translates',$code.'.json'));
        $data_json = json_encode($data,JSON_FORCE_OBJECT);        @file_put_contents($default_language_path_json,$data_json);
    }
    public static function getData($code){
        $default_language_path_json = Path::getPath(array('uploads','translates',$code.'.json'));        $default_language_path_yaml = Path::getPath(array('languages',$code.'.yml'));
        return array(            'cache' => file_get_contents($default_language_path_json),            'origin' => file_get_contents($default_language_path_yaml),        );
    }
    public static function changeSessionLang($lang="en"){        $context =& get_instance();        $context->load->library('session');        $context->session->set_userdata("lang",$lang);        self::getDefaultLangData();    }
    public static function getLangsCodes(){        return self::loadYmls();    }
    public static function test(){        echo "<pre>";        print_r(self::loadYmls());    }
    public static function getDir(){
        if(empty(self::$_translate_data_array)){            self::getDefaultLangData();        }
        $data = self::$_translate_data_array;
        if(isset($data['config'])            AND isset($data['config']['dir'])){
            $data['config']['dir'] = strtolower($data['config']['dir']);            define("__DIR",$data['config']['dir']);            return $data['config']['dir'];        }else{            define("__DIR","ltr");        }
        return "ltr";    }
    public static function sprint($msgId="",$default=""){
        if(self::$in_debugging_mode)            return "*****";
        $msgId = trim($msgId);        $default = trim($default);
        if(empty(self::$_translate_data_array)){            self::getDefaultLangData();        }
        $data = self::$_translate_data_array;
        if(isset($data[$msgId])){
            if(ENVIRONMENT=="development"){
                if(isset($data[$msgId]) and $data[$msgId]==""){                    $_SESSION['toTranslate'][$msgId] = "********** NEED TO TRANSLATE ***********";                }else if(isset($data[$msgId]) and $data[$msgId]!=""){                    $_SESSION['toTranslate'][$msgId] = $data[$msgId];                }
            }
            return ($data[$msgId]);        }else{
            if(ENVIRONMENT=="development"){                $_SESSION['toTranslate'][$msgId] = "********** NEED TO TRANSLATE ***********";            }
            if($default!="")                return $default;            else                return ($msgId);
        }
    }
    public static function sprintf($msgId="",$args=array(),$default=""){
        if(self::$in_debugging_mode)            return "*****";
        if(empty(self::$_translate_data_array)){            self::getDefaultLangData();        }
        $data = self::$_translate_data_array;
        if(isset($data[$msgId])){            if(empty($args))                return $data[$msgId];            else{
                if(ENVIRONMENT=="development"){
                    if(isset($_SESSION['toTranslate'][$msgId]) and $_SESSION['toTranslate'][$msgId]==""){                        $_SESSION['toTranslate'][$msgId] = $default;                    }else if(!isset($_SESSION['toTranslate'][$msgId])){                        $_SESSION['toTranslate'][$msgId] = $default;                    }
                }
                return vsprintf($data[$msgId],$args);            }
        }
        else            return vsprintf($msgId,$args);
    }
    public static function getDefaultLang(){
        $context =& get_instance();        $lngFromSession = $context->session->userdata('lang');        if($lngFromSession!=""){            return $lngFromSession;        }else{            return DEFAULT_LANG;        }
    }
    public static function getDefaultLangData(){
        $context =& get_instance();        $context->load->library('yaml');
        $lngFromSession = $context->session->userdata('lang');        if($lngFromSession!=""){            $fileYaml = Path::getPath(array("languages",trim($lngFromSession).".yml"));        }else if(defined("DEFAULT_LANG")){            $fileYaml = Path::getPath(array("languages",DEFAULT_LANG.".yml"));        }else{            $fileYaml = Path::getPath(array("languages","en.yml"));        }
        if(file_exists($fileYaml)){
            $context =& get_instance();            //load yanl file            $data = $context->yaml->load($fileYaml);            self::$_translate_data_array = $data;
        }
    }
    public static function loadLanguageFromYml($def=""){
        $context =& get_instance();        $context->load->library('yaml');        $lngFromSession = $context->session->userdata('lang');
        if($def!="" && preg_match("#[a-zA-Z]{2}#",$def)){            $fileYaml = Path::getPath(array("languages",trim($def).".yml"));        }else if($lngFromSession!=""){            $fileYaml = Path::getPath(array("languages",trim($lngFromSession).".yml"));        }else{            $fileYaml = Path::getPath(array("languages",DEFAULT_LANG.".yml"));        }
        if(!file_exists($fileYaml)){            $fileYaml = Path::getPath(array("languages",DEFAULT_LANG.".yml"));        }
        if(file_exists($fileYaml)){
            $context =& get_instance();            //load yanl file            $data = $context->yaml->load($fileYaml);
            return $data;        }
        return  array();
    }
    public static function remove($code=""){
        $path_yml =  Path::getPath(array('languages',$code.'.yml'));        $path_json =  Path::getPath(array('uploads','translates',$code.'.json'));
        @unlink($path_yml);        @unlink($path_json);    }
    public static function loadLanguageFromCache($def=""){
        $context =& get_instance();        $context->load->library('yaml');        $lngFromSession = $context->session->userdata('lang');
        if($def!="" && preg_match("#[a-zA-Z]{2}#",$def)){            $fileJSON = Path::getPath(array("uploads","translates",trim($def).".json"));        }else if($lngFromSession!=""){            $fileJSON = Path::getPath(array("uploads","translates",trim($lngFromSession).".json"));        }else{            $fileJSON = Path::getPath(array("uploads","translates",DEFAULT_LANG.".json"));        }
        if(!file_exists($fileJSON)){            $fileJSON = Path::getPath(array("uploads","translates",DEFAULT_LANG.".json"));        }
        if(file_exists($fileJSON)){
            $json = file_get_contents($fileJSON);            return json_decode($json,JSON_OBJECT_AS_ARRAY);        }
        return  array();
    }
    public static function regenerateJson($code,$data){
        $values = array();
        $cached = self::loadLanguageFromCache($code);        $uncached = self::loadLanguageFromYml($code);
        $values = Translate::merge($uncached,$cached);
        foreach ($data as $val){            $values[$val['key']] = $val['value'];        }
        $language = self::loadLanguageFromYml($code);
        $values['config'] = $language['config'];        $values['config']['last_update'] = date('Y-m-d H:i:s',time());
        self::save($code,$values);
        return TRUE;
    }
    public static function merge($array_new_keys, $array_new_values){
        $merged = array();
        //add new keys        foreach ($array_new_keys as $key => $value){            if(!isset($array_new_values[$key])){                if(is_string($value))                    $merged[$key] = $value;            }        }
        //fetch old values        foreach ($array_new_values as $key => $value){            if(is_string($value))                $merged[$key] = $value;        }
        return $merged;    }
    private static function loadYmls(){
        //get instance of object        $context =& get_instance();        $context->load->library("yaml");
        $data_to_json = array();        $path = Path::getPath(array("languages"));
        if(!is_dir($path)){            mkdir($path);        }
        if ($handle = opendir($path) AND $path!="" AND is_dir($path)) {
            while (false !== ($entry = readdir($handle))) {                if ($entry != "." && $entry != ".." ) {
                    //prepare path of files                    $fileYaml = Path::addPath($path, array($entry));
                    //load yanl file                    $data = $context->yaml->load($fileYaml);
                    //prepare config data for lang
                    if(isset($data['config'])                        AND isset($data['config']['name'])                        AND isset($data['config']['version'])){
                        $lng = preg_replace("#.yml#", "", $entry);
                        $data_to_json[$lng] = array(                            "name"  => $data['config']['name'],                            "version"  => $data['config']['version'],                            "lang"     => $lng,                            "dir"       => "ltr"                        );
                        if(isset($data['config']['dir'])){                            $data_to_json[$lng]['dir'] = $data['config']["dir"];                        }
                        unset($data);
                    }
                }            }
            closedir($handle);        }
        return $data_to_json;    }
    public static function parse($code,$fileYaml){
        //get instance of object        $context =& get_instance();        $context->load->library("yaml");
        $data_to_json = array();        $path = Path::getPath(array("languages"));
        if(!is_dir($path)){            mkdir($path);        }
        //load yanl file        $data = $context->yaml->load($fileYaml);
        //prepare config data for lang
        if(isset($data['config'])            AND isset($data['config']['name'])            AND isset($data['config']['version'])){
            $data_to_json = $data;
            if(isset($data['config']['dir'])){                $data_to_json[$code]['dir'] = $data['config']["dir"];            }
            unset($data);
        }
        return $data_to_json;    }
}
if(!function_exists('_lang')){    function _lang($str,$default=''){        return Translate::sprint($str,$default);    }
}

Hi,

Please reset the changes that you made, then try to re-upload attached file at this path 

Path : application/modules/nstranslator/helpers/translator_helper.php

Also please check uploads file if it has permission 777.

I forgot to attach the file, please find it below, you can replace it by old file.