Artisan returns blank

Running composer install solved the problem.

This problem is pretty common and is usually related to some errors that are not seen in the CLI like custom classes that failed to load, are you sure you have error reporting on?

Edit the file artisan and add the following lines just after the PHP opening tag <?php:

ini_set('display_errors',1);
error_reporting(-1);

Try running artisan again and see if there is any output.

If that doesn't work try reverting app/start/global.php to it's default state.