The Most Common Errors During Magento 2 Installation (Part1)

• Installation stops at about 70%
• Cannot install using nginx
• During installation, fatal PDO error displays
• During installation, Reflection Exception error
• Download fails because of changes in Composer

1. Installation stops at about 70%

During installation using the Setup Wizard, the process stops at about 70% (with or without sample data). No errors display on the screen.

Common causes for this issue include:

• The PHP setting for max_execution_time
• Timeout values for nginx and Varnish

Solution:

location ~ ^/setup/index.php {
.....................
fastcgi_read_timeout 600s;
 fastcgi_connect_timeout 600s;
}

backend default {
.....................
 .first_byte_timeout = 600s;
}

service varnish restart

2. Cannot install using nginx

If you use the nginx web server and you attempt to install the Magento software, the installation sometimes fails.

Detail

You can confirm the issue by the following error in the var/report directory:

NOTE: You cannot install Magento using the Setup Wizard because the Magento setup directory cannot be accessed.
You can install Magento using either the command line or you must restore access to the following directory: /var/www/html/setup
If you are using the sample nginx configuration, please go to http://ce.mtf03.bcn.magento.com/setup/";i:1;s:641:"#0 /var/www/html/lib/internal/Magento/Framework/App/Http.php(213): Magento\Framework\App\Http->redirectToSetup(Object(Magento\Framework\App\Bootstrap), Object(Exception))

Workaround

Append /setup to the URL by which you access the Setup Wizard or install the Magento software using the command line.

3. During installation, fatal PDO error displays

Details

PHP Fatal error:  Class 'PDO' not found in /var/www/html/magento2/setup/module/Magento/Setup/src/Module/Setup/ConnectionFactory.php on line 44

Solution:

Make sure you installed all required PHP extensions (CentOS, Ubuntu).

4. During installation, Reflection Exception error

Details

During the installation, a message similar to the following displays:

[ERROR] exception 'ReflectionException' with message 'Class Magento\Framework\StoreManagerInterface does not exist' 
in /<path>/lib/internal/Magento/Framework/Code/Reader/ClassReader.php

Solution

Clear all directories and files under Magento’s var subdirectory and install the Magento software again.

As the Magento file system owner or as a user with root privileges, enter the following commands:

cd <your Magento install directory>/var
rm -rf cache/* di/* generation/* page_cache/*

5. Download fails because of changes in Composer

Symptom

During download, the following error displays:

[ErrorException]
  	file_get_contents(app/etc/NonComposerComponentRegistration.php): failed to open stream: No such file or directory

Description

This happens because of changes in certain versions of Composer.

The workaround is to downgrade Composer to an earlier version and try your Magento download again.

Any version of Composer dated between November 21 and November 26, 2015 has this issue. To confirm this issue is related to the Composer version, enter the following command:

composer -v

The version displays similar to the following:

Composer version 1.0-dev (2b14f0a047dd4f3545ec82381f65c36ea93a4c81) 2015-11-25 17:13:09

Note the date is 2015-11-25, which indicates Composer has this issue.

To work around it:

1. Change your version of Composer to enable you to download the Magento software by doing any of the following:

   • Downgrade Composer using the following command:

     composer self-update 1.0.0-alpha11
      

   • Upgrade Composer to a version later than November 26, 2015:

     composer self-update
      

2. Delete your Magento 2 directory and subdirectories.
3. Try the download again using either composer create-project or git clone.

4. After successfully downloading the Magento software, update Composer:

   composer self-update