Upgrading from 4.3.0 to 4.3.1

Please refer to the upgrade instructions corresponding to your installation method.

Composer Version


If you use Composer, CodeIgniter v4.3 requires Composer 2.0.14 or later.

If you are using older version of Composer, upgrade your composer tool, and delete the vendor/ directory, and run composer update again.

The procedure, for example, is as follows:

composer self-update
rm -rf vendor/
composer update

Mandatory File Changes

Config Files


  • If you updated app/Config/Email.php when upgrading to v4.3.0, you must set the default values to $fromEmail, $fromName, $recipients, $SMTPHost, $SMTPUser and $SMTPPass to apply environment variable (.env) values.

  • If no default values are set, setting environment variables for them will not be reflected in the Config object.


  • If you are using PHP 8.2, you need to add new properties $logDeprecations and $deprecationLogLevel.

Project Files

Some files in the project space (root, app, public, writable) received updates. Due to these files being outside of the system scope they will not be changed without your intervention.

There are some third-party CodeIgniter modules available to assist with merging changes to the project space: Explore on Packagist.

Content Changes

The following files received significant changes (including deprecations or visual adjustments) and it is recommended that you merge the updated versions with your application:


  • app/Config/Email.php
    • Set the default value '' to $fromEmail, $fromName, $recipients, $SMTPHost, $SMTPUser and $SMTPPass to apply environment variable (.env) values.

All Changes

This is a list of all files in the project space that received changes; many will be simple comments or formatting that have no effect on the runtime:

  • app/Config/Email.php

  • composer.json