Problem: Change directory to Drupal 8/9 instance, and run composer require drupal/console  Then, this error occur: Solution: Install 2 missing modules by running the below composer commands: composer require symfony/filesystem:”4.4.8 as 3.4.35″ composer require symfony/finder:”4.4.8 as 3.4.35″ Then run the composer require drupal/console  again.