Erros ao instalar projeto

ErrorException  : Return value of "Illuminate\Foundation\Console\PackageDiscoverCommand::execute()" should always be of the type int since Symfony 4.4, NULL r
eturned.

  at C:\Projeto-Laravel1\controle-series\vendor\symfony\console\Command\Command.php:258
    254|         } else {
    255|             $statusCode = $this->execute($input, $output);
    256|
    257|             if (!\is_int($statusCode)) {
  > 258|                 @trigger_error(sprintf('Return value of "%s::execute()" should always be of the type int since Symfony 4.4, %s returned.', static::class
, \gettype($statusCode)), \E_USER_DEPRECATED);
    259|             }
    260|         }
    261|
    262|         return is_numeric($statusCode) ? (int) $statusCode : 0;

  Exception trace:

  1   trigger_error("Return value of "Illuminate\Foundation\Console\PackageDiscoverCommand::execute()" should always be of the type int since Symfony 4.4, NULL r
eturned.")
      C:\Projeto-Laravel1\controle-series\vendor\symfony\console\Command\Command.php:258

  2   Symfony\Component\Console\Command\Command::run(Object(Symfony\Component\Console\Input\ArgvInput), Object(Illuminate\Console\OutputStyle))
      C:\Projeto-Laravel1\controle-series\vendor\laravel\framework\src\Illuminate\Console\Command.php:170

  Please use the argument -v to see more details.
Script @php artisan package:discover --ansi handling the post-autoload-dump event returned with error code 1