During installation, exception SessionHandler::read()

This article provides a fix for an exception SessionHandler::read() error during Adobe Commerce installation.

Issue

At the last step of installing Adobe Commerce, the following exception displays:

exception 'Exception' with message 'Warning: SessionHandler::read():
open(..) failed: No such file or directory (2) ../magento2/lib/internal/Magento/Framework/Session/SaveHandler.php on line 74'
in ../magento2/lib/internal/Magento/Framework/App/ErrorHandler.php:67

NOTE

This error occurs only in code versions earlier than September 28, 2015. If you install code dated September 29 or later, this error should not occur. For more information about configuration options for Redis, see Configure Redis in our developer documentation. For more information about specifying Redis using the command-line installer, see the installation topic or the deployment configuration topic in our developer documentation.

Cause

This happens when your session.save_handler PHP parameter is set to some another session storage than files (for example, redis, memcached, and so on). This is a known issue we're working to resolve.

Solutions:

Upgrade your Adobe Commerce code. Refer to Installation Guide > Update the Adobe Commerce software in our developer documentation.
Use the following workaround with existing code:

Locate php.ini

Locate php.ini by entering the following command:

php -i | grep "Loaded Configuration File"

Typical locations follow:

Ubuntu: /etc/php5/cli/php.ini
CentOS: /etc/php.ini

Workaround

As a user with root privileges, open php.ini in a text editor.
Locate session.save_handler
Set it in any of the following ways:
- To comment it out:
```
;session.save_path = <path>
```
- To set it to a file system path:
```
session.save_handler = files
```