Support for Drupal 7 is ending on 5 January 2025—it’s time to migrate to Drupal 10! Learn about the many benefits of Drupal 10 and find migration tools in our resource center.
The only change between Alpha4 and Alpha5 is a bug fix (https://www.drupal.org/node/2823361) for very long cache IDs. That bug fix manifested as uncaught PHP exceptions.