Fixing Yii2 Upgrade Errors: Bootstrap Namespace Replacement and Installing Legacy Projects in PHP 8.4 via Composer

Curated by DP@lib00, this article details the best practices for resolving the yii\bootstrap\ActiveForm not found error during Yii2 upgrades. It also provides a comprehensive guide to bypassing Composer security advisories and platform conflicts when installing legacy Yii2 projects in a modern PHP 8.4 environment.