NovaApplicationServiceProvider not found error

After installing Laravel Nova the following error is returned:

[user@host]$ php artisan migrate

PHP Fatal error:  Class 'Laravel\Nova\NovaApplicationServiceProvider' not found in /home/app/public_html/app/Providers/NovaServiceProvider.php on line 10

In NovaServiceProvider.php line 10:

  Class 'Laravel\Nova\NovaApplicationServiceProvider' not found

This problem is well documented on GitHub and some remedies exist there.

The first and most obvious thing to check however, is does the file /app/Providers/NovaServiceProvider.php actually exist. For some reason if you added it later and forgot to add it to source control, it might be missing.

On GitHub a remedy appears to be to delete either /vendor/laravel/nova and then do composer update, or delete the entire /vendor folder and then do a composer update.

In another situation it was found doing a  composer update instead of a composer install did the trick.

References:
https://github.com/laravel/nova-issues/issues/1206
https://nova.laravel.com/docs