Fix ‘Namespace_Module_Helper_Data’ not found fatal error in Magento ?

Following are the steps to resolve”fatal error: Class ‘Namespace_Module_Helper_Data’ not found” error.

  1. Install the extension when compilation is disabled in Magento admin.
  2. To check whether compilation is enabled or disabled, go to
    Admin > system >Tools > compilation  check enabled / disabled
  3. If enabled, then disable it and install the extension. Once the extension is installed you can enable compilation again by using ‘Re-run Compilation.
  4. If you have already installed the extension & are facing the above error, Disable the extension from app/etc/modules/Namespace_Module.xml
  5. <active>true</active> 
  6. Clear cache from var/cache folder.
  7. Now you will have the access to Magento admin panel from where you can disable the compilation.
  8. Now enable the extension from Namespace_Module.xml
  9. <active>false</active>
  10. Clear cache from var/cache folder.

How to install vQmod

Install vQmod in opencart :

If you have opencart version or above, you don’t need to install vQmod. Opencart or above already install vQmod ( exactly called OCMOD ).

It is for opencart or below versions.

Here is the following steps to install vQmod.

  1. Download the latest version of vQmod form here. You have to download vQmod version with opencart. Standalone version is not compatible with opencart.
  2. Extract the archive and copy all files in the your OpenCart root directory. File structures of opencart root directory is given below.
    - admin
    - catalog
    - download
    - image
    - system
    - vqmod
    --- install
    --- vqcache
    --- log
    --- xml
  3. Give write access permission to following files:
    - index.php
    - admin/index.php
    And directories :
  4. Openlink link in the browser :

If you have done everything, you will see this message on browser : ‘VQMOD HAS BEEN INSTALLED ON YOUR SYSTEM!‘.

Magento2: Composer and Installation

Magento now uses Composer to install the Magento software. Composer enables Magento to manage the Magento components and their dependencies.

If You have already installed Composer then go for the Next step, for the installation of Magento2 setup.

Anyone who uses the Magento software must install Composer to update components and Magento Ssoftware. If you install Magento using an archive or setup, you don’t need Composer to install Magento, but for getting updates you do need Composer.

Composer provides following advantages:

  • Enables to reuse third-party libraries without bundling them with source code
  • Component-based architecture with robust dependency management
  • Manages dependencies to reduce extension conflicts and compatibility issues
  • Versioned dependencies
  • Semantic versioning
  • Supports PHP Framework Interoperability standard

Install Composer

First, check if Composer is already installed:

In a command prompt, enter any of the following commands:

  • composer --help
  • composer list --help

If command help displays, Composer is already installed; in that case, you can skip the next section and continue with magento installation.

If an error displays, use the following steps to install Composer.

To install Composer:

  1. Change to or create an empty directory on your Magento server.
  2. Enter the following commands:
    curl -sS | php
    mv composer.phar /usr/local/bin/composer

    For additional installation options, see the Composer installation documentation.

Magento2: Command Line or Terminal installation on Ubuntu

A long-waited Magento2 now appeared on Magento site for installation. Of course we couldn’t sit still and installed Magento2 on our server. And described the installation process for you, including the issues we dealt with and how we fixed them.

Pre Installation

The first steps lead us to the installation guide page. It is required to check whether your server suits minimal Magento 2 requirements:

Apache: 2.2 or 2.4

PHP: 5.5.x or 5.6.x

MySQL: 5.6.x


As we are using Ubuntu 14.4,  so the system suits minimal database requirements, and we already have PHP 5.5.x support. Also you’ll need Git and Composer, install it if you haven’t done it before.

Use these commands in command line or terminal for root user permissions:

apt-get update
apt-get install git wget
wget -O /usr/local/bin/composer
chmod +x /usr/local/bin/composer

Magento 2 download

Now it’s time to clone Magento 2 code from GitHub repository. http://magento2/ is the URL of our website, and the document root is /var/www/magento2. Use these commands if you don’t plan to install Sample data for Magento 2:

cd /var/www 
git clone
cd /var/www/magento2
composer install

If you plan to install Sample data – refer to this link for details. As for now Magento 2 is still under development, the best variant is to read the latest documentation at Magento docs.

File permissions

create a root user, which is the owner of all magento files on your server, and Apache web server runs on behalf of ‘www-data’ user. Magento 2 documentation describes the access permission settings for files and directories on the principle that the web server runs on behalf of the user which is the owner of all Magento files. Our opinion is: it’s not the best decision, as it can lead to security issues (as the web server has permissions to write and run the code) as well as issues with setting access permissions for third party developers (as you’re not logging in as www-data user). We normally use the following access permissions:

chown -R :www-data /var/www/magento2
find /var/www/magento2 -type f -print0 | xargs -r0 chmod 640
find /var/www/magento2 -type d -print0 | xargs -r0 chmod 750
chmod -R g+w /var/www/magento2/{pub,var}
chmod -R g+w /var/www/magento2/{app/etc,vendor}


now create database –

echo 'CREATE DATABASE `magento2` DEFAULT CHARSET utf8 COLLATE utf8_general_ci; GRANT ALL PRIVILEGES ON `magento2`.* to `magento2`@`%` IDENTIFIED BY "magento2";' | mysql -h mysql56.local -u root -p

Magento2 installation

Now all is set start you magento installation using below command

/var/www/magento2/bin/magento setup:install --base-url=http://magento2/ --db-host=localhost --db-name=magento2 --db-user=root --db-password=root --admin-firstname=a2bizz --admin-lastname=user --admin-user=a2bizz --admin-password=a2bizz@123 --language=en_US

Magento2: Step by step installation

As we are known of pre installation requirements of magento2 software installation, now we starting to install magento2 step by step, if you have not gone through the pre installation process and system requirements for magento2 installation, then go through our pre-installation article for magento2

For installation we are using Linux system Operating system Ubuntu version 14.04

Step 1 – Extarct your zip installation file –

copy your installation magento2 zip folder to the desired location of your server, or in your local computer, it will be – /var/www/html/magento2. In magento2 folder extract your magento installation files.


Now hit your magento2 url, it should be http://localhost/magento2/ and screen will be displayedsetupStart

If this installation screen not comes in first attempt, then change the permission of var directory to 777, inside your root directory in extracted files.

Now click button Agree and Setup Magento

Step 1 – Rediness Check

A next will come in this screen click button “Start Rediness Check”, this will check the basic requirements to install magento2.




See what is required and fullfil that

Step 2 – Add a Database –

create a database in you host/ localhost and fill the details, if you do not have mysql version 5.6 or later then setup will show error.

Add a Database



Step 3 – Web Configuration –

here set your admin address, write the name for your admin, for example – we have given a admin address as “admin”.

Step 4 – Customize Your Store –

here set your currency, language and time zone

Step 5 – Create Admin Account –

here set the admin user name and password for your magento2 application.

Step 6 – Install –

Now all set, you click on start and your installation process will start.

Magento2: Pre Installation process

Before we go into the installation process, first we need to check the Magento basic sytem requirements –


for more information – please visit magento official documentation URL

After setting and fulfill all basic system requirements, now you download latest magento2 version, which we can download from , here you will see two types of packages, one without and another with Sample data, whatever package you want you can install, if you want to install magento2 for testing purposes, then go for magento2 package with Sample data.


Now you have completed all pre-installation process requirement, go for the next Step By Step process for magento2 Installation