seancojr
4/3/2016 - 2:46 AM

If you see an error like "Fatal error: session_start(): Failed to initialize storage module: user (path: ) in .../code/wp-content/plugins/pl

If you see an error like "Fatal error: session_start(): Failed to initialize storage module: user (path: ) in .../code/wp-content/plugins/plugin-that-uses-sessions/example.php on line 2" you likely have a plugin in the mu-plugins directory that is instantiating a session prior to this plugin loading. To fix, you will need to deactivate this plugin and instead load it via an mu-plugin that loads first, e.g. create an mu-plugin called 00.php and add a line in it to include the wp-native-php-sessions/pantheon-sessions.php file and the problem should disappear.

From https://wordpress.org/support/topic/including-this-plugin-via-an-mu-plugin?replies=2

wp-native-php-sessions.php
content_copyfile_download
<?php
/*
  Plugin Name: MU WP Native PHP Sessions
  Plugin URI: https://wordpress.org/plugins/wp-native-php-sessions/
  Description: Building on Pantheon's and WordPress's strengths, together.
  Version: 0.1
  Author: Pantheon
  Author URI: http://getpantheon.com
*/

if ( isset( $_ENV['PANTHEON_ENVIRONMENT'] ) ) :

require_once( 'wp-native-php-sessions/pantheon-sessions.php' );

endif; # Ensuring that this is on Pantheon