Laravel 5.6: Uncaught ReflectionException: Class env does not exist

When running my Laravel 5.6 application on it's production server, I'm getting an error as follows both in the browser and in the console when trying to run artisan commands:

PHP Fatal error:  Uncaught ReflectionException: Class env does not exist in /var/www/html/service.straightlinefernie.com/dev/vendor/laravel/framework/src/Illuminate/Container/Container.php:767
Stack trace:
#0 /var/www/html/service.straightlinefernie.com/dev/vendor/laravel/framework/src/Illuminate/Container/Container.php(767): ReflectionClass->__construct('env')
#1 /var/www/html/service.straightlinefernie.com/dev/vendor/laravel/framework/src/Illuminate/Container/Container.php(646): Illuminate\Container\Container->build('env')
#2 /var/www/html/service.straightlinefernie.com/dev/vendor/laravel/framework/src/Illuminate/Container/Container.php(601): Illuminate\Container\Container->resolve('env', Array)
#3 /var/www/html/service.straightlinefernie.com/dev/vendor/laravel/framework/src/Illuminate/Foundation/Application.php(734): Illuminate\Container\Container->make('env', Array)
#4 /var/www/html/service.straightlinefernie.com/dev/vendor/laravel/framework/src/Illuminate/Container/Container.php(1210): Illuminate\Foundation\Application->m in /var/www/html/service.straightlinefernie.com/dev/vendor/laravel/framework/src/Illuminate/Container/Container.php on line 767

The app runs fine on my development environment. I've combed my .env and config/ files for errors, and it all appears good.

I'm guessing there is something missing in my server set up, but the main problem as I see it is that this error message is too generic and doesn't provide the information required to discover what specific file or error is actually making the boot process fail.

The stack trace is not even saved in the log file, and appears only in the console when I try to run artisan commands.

Does anyone know how to get a more detailed error message that can actually help me solve this error?

Perhaps there is a way to edit the file Illuminate/Container/Container.php so that it gives me more info?

Thanks